‘We should havedone this earlier’p.22

A ﬁghter jet andyour health. Radar
can track both p.6

Help from on highto solve earthly
problems p.36

Airplanes
cross borders
p.46

In search of
the plastic soupp.72

FUNDAMENT‘A treasure
trove of stories’fundament

TABLE OF CONTENTS

Table of contents
Mechanical engineeringand Aerospace

Civil engineering

Hit the roads safely with autonomousvehiclesBridges are becoming circular

LAURA FERRANTIAutonomous robots protect the livesof emergency services in disasters
ANAHITA JAMSHIDNEJAD

Using smart technology to makefuel out of CO2
PEYMAN TAHERI

Is hydrogen-powered air travel
the future?
IVAN LANGELLA

Airplanes cross borders
IRENE DEDOUSSINature inspires new materials
MOHAMMAD J. MIRZAALIFlinging tiny autonomous satellites
at earth
STEFANO SPERETTA

In search of the plastic soup
ANGELIKI LASKARI

1014WENJUN CAO

Help from on high to solve earthly
problems
GIORGIA GIARDINA

Good vibrations? Not for bridges
ALICE CICIRELLOElectrical engineering

18

A ﬁghter jet and your health.
Radar can track both
FRANCESCO FIORANELLI

36

Terahertz waves for next generation
sensing and communication
MARIA ALONSO-DELPINO

50

28

RAJENDRA BISHNOI

46

And further

58

From priority area to Sector Plan
to science64
72

Future research
ALEKSANDRA LEKIĆ, SHOSHANABRAHAMI, KSANDER DE WINKEL,
MATIN JAFARIAN, SID KUMAR

32

City of the future communicates using
solar panels
PATRIZIO MANGANIELLO
54
Living on the edge

40

6

68

PROF. DR. H.G.C. WERIJ

2

Reading guide

426

HANIEH BAZYAR, LAURA MARCHALCRESPO, DOMINIC VON TERZI, SIJUN
DU, BARIS CAGLAR, DIMITRIS BOSKOS,
ANDRES HUNT44
BRAM VAN DEN EIJNDEN, LAURASTANCANELLI, ORIOL COLOMÉS GENE,TON STEFAN VAN DEN BREMER,JOSÉ ANTONIO ALVAREZ ANTOLINEZ,
IURI B.C M. ROCHA
62‘we should have done this earlier’
HANS HELLENDOORN, LINA SARRO,GUIDO DE CROON AND BERT SLUYS

22Colofon76

1

fundament

INTRODUCTION

PROF. DR. H.G.C. WERIJ

Itʼs not often we put the spotlight on research

euro, funding 17 positions at the Faculty ofstories based on the way they were funded. In

Mechanical, Maritime and Materials Engineering

fact, for the researchers themselves as much as(3mE), 7 at Aerospace Engineering (AE), 12 at

for the outside world, it is all too easy to forget

Civil Engineering & Geosciences (CEG) and 11

about the mechanisms that are in place toat Electrical Engineering, Mathematics andensure the continuing success of research at our

Computer Science (EEMCS). The positions coveruniversity. And this is unfortunate, as the Sector

a wide range of priority areas, from advanced

Plans have been pivotal in supporting scientiﬁcmaterials under extreme conditions via human-

research when it was most needed.

robot interaction to soil mechanics. However
diﬀerent they may be, they are all driven by the

Dean Aerospace Engineering

So, allow me to take you back to 2018, whencuriosity of the scientists working on them.

increasing student numbers and a trend towards

from priority
area to sector
plan to science
Scientiﬁc research oﬀers a treasure trove of stories. Stories about visions for the
future, lots of hard work, unexpected challenges, tentative progress and sometimes

application-oriented research were as exciting

Even though it is early days, and some positions

as they were stretching our core knowledge

are still being ﬁlled, I can already say that the

infrastructure to the limit. In the four engineering

Sector Plans are a resounding success. Not only

faculties (AE, 3mE, CEG and EEMCS), the numberin terms of bringing extraordinary talent to theof students almost doubled between 2008 anduniversity and decreasing the teaching workload,

2018. As teaching staﬀ numbers didnʼt increase to

but also by strengthening coordination among thethe same extent, our scientists found themselves

Dutch universities and by providing shared tools

having less and less time for research within

to provide much needed gender diversity within

the basic disciplines. The Dutch government,

the engineering landscape.

recognising this as the foundation of beta
sciences asked the universities to identify the

In this magazine, we introduce you to all the

areas that needed strengthening most, and do soresearchers at TU Delft funded by the engineeringin national coordination. Within the engineering

part of the Sector Plans. Fifteen of them areﬁeld, 21 of our existing priority areas werecurrently featured on our Stories platform, andselected, spread over the three disciplines of

we reproduce their stories here. We also discuss

mechanical engineering, civil engineering andthe 21 priority areas of the engineering Sector

electrical engineering. Individual universities

Plans, and asked 4 priority area coordinators toand, ﬁnally, faculties translated this national

talk about how the Sector Plans are working out

prioritization into a wish list of personnel

in practice.

positions: the Sector Plans.

breakthroughs. In short, the daily adventures of science. TU Delft continuously talks
to its researchers to learn about these stories, sharing them on its Stories platform(tudelft.nl/stories). The magazine you are reading now collates sixteen stories that2

I hope you will enjoy reading this magazine!
Thanks to the Sector Plans we could hire
talented tenure track researchers as well as

On behalf of the four faculties at TU Delft taking

senior staﬀ working on important topics thatpart in the engineering Sector Plans,

have one thing in common: the research they tell about, was funded through theare at the heart of the technical sciences. For

Sector Plan funds of the Dutch government.

Delft, this speciﬁcally meant about 7,4 million

Prof. dr. H.G.C. Werij, dean Aerospace Engineering3

fundament

READING GUIDE

Reading
Delft University of Technology is committed to having signiﬁcant, if not leading, impact regarding some of themost prominent challenges the world and our society are facing today. Rapid changes in technology are taking
place, but in some areas the required changes are not occurring fast enough. Sometimes a revolution is needed
rather than an evolution. This is why the Sector Plan funds of the Dutch government were established.
This Fundament magazine of TU Delft should be read in the framework of the Engineering part of the Sector
Plans. The focus is on the technical disciplines agreed for the Engineering Sector Plan: Mechanical engineeringand Aerospace, Electrical engineering and Civil engineering. Each discipline has chosen priority areas thathave been aligned with other universities involved. Each story highlighted in this magazine shows both thecorresponding discipline and its priority area.

TU Delft is active within two Sector Plans:Within the framework of the Engineering
part of the Sector Plans the following

engineeringbeta

Mechanical engineering and Aerospacemechanicalaerospace

Electrical engineering

Civil engineering

electricalcivil

priority areas are reinforced within eachdiscpline:

1. Advanced materials for extreme conditions

1. Autonomous sensor systems

1. Computational mechanics of materials

2. Autonomous and self- learning control

2. Wireless communication and sensing

2. Dynamics and monitoring of structures and3. Data-driven modelling and control

3. Health and well-being

4. Distributed miniaturized instruments for Space

4. Microgrid components and networks

5. Flow dynamics for low-carbon systems

5. Digital power systems

6. Human-Robot interaction

6. Unconventional electronics and computing systems

7. Multiphase ﬂow for low-carbon systems

infrastructural components
3. Fluid dynamics and sediment transport in humaninﬂuenced marine, inland and urban water systems
4. Fluid structure interactions for infrastructure and fornature based solutions

8. Sustainable design and manufacturing of materials

5. Interface and multi-scale mechanics of structures

9. Turbulent ﬂow and heat transfer

6. Materials and environment
7. Soil mechanics

4

5

fundamentelectrical

A FIGHTER JET AND YOUR HEALTH, RADAR CAN TRACK BOTH

MICROELECTRONICS

A fighter jet and your healthand walks, for example, and in what activities heRadar cantrack bothor she (no longer) engages.ʼ This is very useful
information from a medical perspective, as
research has shown that walking speed, step sizeand general level of activity are strong indicatorsof your state of health. The idea is for such a radarsystem to be embedded into a corner of a room,or even an armchair, rather than having people
carry around some measurement device thatthey may ﬁnd cumbersome or even forget about
entirely. ʻIn our group, we develop the tools toprove these applications in a laboratory setting,ʼ
Francesco says. ʻAfter that, other parties areneeded to continue development for real-world

Any kind of sensing, human or not, unveils similarities. Ice and metal may both feelcold. The sun and an apple may both appear to be red. For Francesco Fioranelli,
specialised in using radar technology for the classiﬁcation of objects, there is little
difference between a ﬁghter jet manoeuvring at tens of kilometres distance, or anelderly person staggering through a room.

applications.ʼ

A new way of looking, even for radar

Having only arrived in the Netherlands abouta year ago, Francesco already wrote, and wasrecently awarded, an NWO Klein grant (“RADART”) for investigating a very novel methodology

Francesco Fioranelli is fascinated by perceiving

focusses on increasing the intelligence of radarfor processing radar data. ʻThe majority ofthe environment beyond the senses available– creating algorithms that use Machine Learning

methods in the literature try to interpret radar

to us as a human being. ʻRadar is an idealclassiﬁcation to make sense of the patterns of thedata as images,ʼ he says. ʻThey therefore use

technology for distinguishing objects and theirradar data. Originally, he applied his knowledge

algorithms that are based on, or at least similar to,

movements, without touching them,ʼ he says. ʻByfor the more traditional surveillance purposes,

those used for image processing. But that is notbouncing electromagnetic waves of the surface ofsuch as ensuring safe routing for aircraft andan object, we can measure its location and speed,

vessels. But he was quick in realising that thewhen near or far, in rain, fog and darkness.ʼ As

continued miniaturization and cost reduction

an assistant professor in the Microwave Sensing,in radar technology has opened up many new

Signals and Systems group, Francesco mostly

opportunities.

Not such a big step

One of these opportunities is the applicationof radar for tracking your health in your homeenvironment, raising the alarm before you
are so unwell that you need highly specialised
and expensive care. It is not such a big stepfrom airspace surveillance as you may think.
ʻWith some tweaking, the algorithms I used
for processing radar data to identify drones at‘Using radar to track your health in yourhome environment is about raising thealarm before you need highly specialised
and expensive care.’6

necessarily how radar works. Radar is a stream

several kilometres distance are just as applicableto tracking the motion of a person in a room,ʼFrancesco says. ʻBy looking at radar data, we
can infer a lot of useful information about the
wellbeing of a person. How that person moves‘Radar is an ideal
technology for
distinguishingobjects and their
movements, without
touching them.’
7

fundamentelectrical

A FIGHTER JET AND YOUR HEALTH, RADAR CAN TRACK BOTH

‘By analysing radar
data of human motion
as if it were musicor speech, rather
than images, we are
venturing into very
new territory.’

MICROELECTRONICS

of pulses being send and received in a constant

Likewise, the car needs to be able to distinguishsequence.ʼ In his RAD-ART project, Francesco

a tree or lamppost next to the road from awill therefore look at Artiﬁcial Intelligence

person, as the latter may decide to cross thetechniques that are inspired by the study ofroad at any moment.ʼ One way the researchers

sound, speech and music. The primary focus oftry to improve this situational awareness is by

this research is the analysis of human motion intraining a radar system using data obtained

a domestic setting – to see if with some tweaks,

with optical cameras. ʻWe are working towards

these techniques will help in training a radara laboratory setup where we have a camera andsystem to understand the large variety in humanvarious radar boards looking at the same scene,

movements. But the same algorithms can also becollecting data simultaneously,ʼ Francesco says.

used for other applications such as surveillance

ʻThe department is also considering buying– think of a drone hovering somewhere andsome target simulators. Rather than having tothen suddenly accelerating towards an airport.

go through the cumbersome process of building

Francesco: ʻWe are venturing into very new

real-life scenarios, these devices can simulate

territory. It could well be that in four years we

how radar echoes will look for a given radar andconclude that it doesnʼt work.ʼ

several targets, speeding up data-acquisition

FRANCESCO FIORANELLI
Assistant Professor Microwave Sensing,
Signals and Systems (MS3)tremendously.ʼ
A tree wonʼt cross the road

By integrating and fusing multiple types of
sensors – such as optical cameras, laser ranging(lidar) and radar – autonomous cars canoperate safely under any weather circumstancesand darkness.

A perhaps somewhat better-known, but still quite

Radar to the rescue

new application of radar is its use in autonomous

Francesco is convinced that his research can havecars. By integrating and fusing multiple types ofa positive impact on the world, but also clear

sensors – such as optical cameras, laser ranging

about radar not being the answer to everything.

(lidar) and radar – autonomous cars can operate

ʻRadar may never be able to beat high-quality

safely under any weather circumstances andmedical devices,ʼ he says, ʻbut it may oﬀer adarkness. Francesco and his colleagues work

cheaper and less invasive solution, allowing

on the interpretation of these radar signals toa personʼs health to be monitored outside of a

get an awareness of the surroundings. Again, it

hospital setting.ʼ It will take some years for radaris about object recognition. ʻThese radar data

to make it into our homes and cars, and those oflook like blobs,ʼ Francesco says. ʻWe want to, for

our ageing parents. Until then, when in traﬃc,example, be able to say if these blobs represent

you may at times still have to rely on your ﬁghtera big truck in the opposite lane or perhaps ajet-inspired evasive manoeuvres.

car using your lane to overtake another car.

‘We want to raise the situational awarenessof car radar by training these systems using
data obtained with optical cameras.’

89

fundament

HIT THE ROADS SAFELY WITH AUTONOMOUS VEHICLES

mechanical

HUMAN-ROBOT INTERACTIONʻA cyclist who looks over
his shoulder a few times
and then sticks out his
hand is easy to notice.

RESEARCH FOCUS: ROBOT NAVIGATION NEAR HUMANS

hit the roads safely
with autonomousvehiclesBut someone who turns
the handlebars with nowarning isnʼt. Still, thecar has to take both into
account.ʼ

When the time comes for autonomous cars to hit the roads,
theyʼll have to take other road users into account. For example,
theyʼll need to stop when a cyclist abruptly turns. Laura Ferranti
is studying how this can be best achieved. Even when roads arepacked with traﬃc.
Imagine, youʼre driving your car through the centre of Delft,
guiding the vehicle along the picturesque canal-side houses
and over a quaint bridge. Before you turn oﬀ, two cyclists speed
by at the last moment. After theyʼve passed by and you want toaccelerate, a father with a pram quickly crosses the road just in
front of you. This isnʼt an unusual scene in the busy centres ofDutch cities. Road users are used to it by now.
ʻBut these situations are extremely diﬃcult for technology to ﬁgure
out,ʼ says Laura Ferranti. Sheʼs a researcher at the Department of
Cognitive Robotics at TU Delftʼs 3mE Faculty. ʻHow does a car know
exactly when someone is about to cross, and how do you make sureYouʼre trying to predict

you notice all those two-wheelers speeding by? These are obviously

something thatʼs quite

things we need to sort out if we want to make a car thatʼs nearly

unpredictableor completely autonomous. At the same time, you donʼt want thevehicle to remain stationary all the time just because itʼs afraid tomove in any direction whatsoever as a result of all the other road
users.ʼ

10

11

fundamentmechanical

HIT THE ROADS SAFELY WITH AUTONOMOUS VEHICLESHUMAN-ROBOT INTERACTION

ʻThey estimate whether a pedestrian will cross a roador a cyclist will make a turn and precisely when. They
do this using sensors, such as cameras and GPS that tellthe vehicle where these pedestrians and cyclists are. And

LAURA FERRANTIAssistant Professor at the
department of Cognitive
Robotics (CoR).

radar plays its part too, as it makes a 360-degree image ofthe surroundings. We use that information to estimate thesays Ferranti. ʻAs researchers, we ensure thatvehicles will drive, sail and ﬂy safely in the future.
But itʼs also important to think about privacy. A
great deal of data is being collected, and we takeimages of other road users. You have to make surecarʼs possibilities. We want to determine which routes thethat everything is well protected. Weʼre alreadycar can take to safely reach its destination.ʼ

thinking about this as well.ʼ
This technology is still developing, so theautonomous car is still a vision of the future. The
fact that Ferranti is working on the traﬃc of the

Robots and humans working together

To achieve this, you to have an accurate idea of

future is not entirely coincidental. She used toThatʼs why Ferranti is working on solutions withwhat people are going to do and how to process

be fascinated by the roads in Rome, where shecolleagues from Dariu Gavrila and Javier Alonso-

this information in order to safely continue

was born and raised. ʻThe traﬃc criss-crosses

Moraʼs team. Theyʼre developing technology thatdriving. The carʼs system interprets this, as

all over the place there. Cars switch lanes at awill allow vehicles to detect everything around

it were, by reading body language, posture,

momentʼs notice, scooters zigzag in between

them and know when they can and cannot

movements and the direction a person is going in.

everything, and then there are the pedestrians

accelerate. So itʼs a technology of the future.

A cyclist who looks over his shoulder a few times

who cross whenever they please. Itʼs a nightmare

You could view this kind of autonomous car as

and then sticks out his hand is easy to notice.

for traﬃc experts. At the same time, itʼs also verya driving robot. In recent decades, robots were

But someone who turns the handlebars with nointeresting. Because in the future, autonomous

usually hidden behind the high walls of factories,

warning isnʼt. Still, the car has to take both intocars are going to have to learn to read andwhere they assembled electronics, for example.

account.

understand these kinds of situations too. I often

ʻBut the new generation really must work together

think about this during my research.ʼ

with humans. It wonʼt be long before we see these

Predicting the unpredictablerobots on our streets.ʼ

ʻUltimately, several (partly) autonomous vehicles

This practical approach characterises Ferrantiʼswill share this information with each other inmethod as a scientist. She started out as aThis means that vehicles will be constantly

the future,ʼ Ferranti says. In addition to cars, it

researcher who liked to focus on theory.

predicting which route is the safest to follow.

will also include ships and drones delivering

ʻI enjoyed working on abstract problems andʻThey estimate whether a pedestrian will cross apackages. The idea is to make things safer by

made many calculations. Now I focus on realistic

road or a cyclist will make a turn and precisely

sharing information. Another vehicle may haveand practical problems: how robots can safely

when. They do this using sensors, such asa better view of road users, which will help yourmove among humans. Suddenly, very diﬀerent

cameras and GPS that tell the vehicle wherecar make the most accurate estimation possible.

uncertainties come into play. Itʼs much morethese pedestrians and cyclists are. And radar

ʻThe vehicles also communicate where they arecomplex. Thatʼs why I found it a bit scary at ﬁrst.

plays its part too, as it makes a 360-degree image

going. So if you make a turn, other road users

But that has changed in the meantime. Now,of the surroundings. We use that information

will receive that information as well. So youʼreworking on real problems and trying to solve

to estimate the carʼs possibilities. We want tohelping each other.ʼ Vehicles will therefore

them appeals to me. But the ﬁeld of research

determine which routes the car can take to safely

continuously communicate with each other. Thisremains exciting, because youʼre trying to predictreach its destination.ʼ

must be done in a safe and responsible manner,something thatʼs quite unpredictable.ʼ

12

13

fundament

AUTONOMOUS ROBOTS PROTECT THE LIVES OF EMERGENCY SERVICES IN DISASTERS

aerospace

AUTONOMOUS AND SELF-LEARNING CONTROL SYSTEMS

Search and rescue robots play an important role in rescue missions following
disasters. Anahita Jamshidnejad is trying to make these robots even more
intelligent so that they can make decisions autonomously in complex
situations, thereby relieving rescue workers of life-threatening tasks andmaking rescue operations more eﬃcient.
Every second counts in the initialsight or the risk of explosion andfrom inhabitants by ﬁreﬁghters,

response to disasters such as ﬁres

collapse. Sending in a search andwho were still inside trying toand earthquakes. If help comes

rescue robot ﬁrst enables us toextinguish the ﬁre. Suddenly the

too late, or if rescue workers

limit risks since robots can collectbuilding collapsed before our eyes,

assess the situation incorrectly,

information even from places thatwhich led to the death of over thirty

this may result in many victims.

are dangerous or inaccessible torescue workers. I believe if robots

In recent years robots, including

humans.’had been used to make a risk

drones, have been increasingly

Autonomous robots
protect the lives of
emergency services
in disasters
14

assessment ﬁrst, this tragic endingused to assist in search andMajor fire as motivation

could have changed for a happy

rescue missions, says Anahita

In early 2017, Jamshidnejad

one. During my PhD programme in

Jamshidnejad, assistent professor

experienced at close hand the

System and Control Engineering,at the Control and Operations

importance of eﬃcient rescue

I had already done research on

department. ‘A drone is a great

efforts. ‘Together with my family,

autonomy of systems via artiﬁcial

tool for assessing situations,

we were watching a live TV

intelligence and model-based

damages or risks in a building

broadcast of a rescue operation

control, although my researchor area. In particular when thein a burning landmark building in

was mainly theoretical. The ﬁresituation is unknown and may pose

my hometown Teheran. The TV

in Teheran motivated me to starta high risk to the lives of rescue

reporter had just announced thatusing my expertise for practicalworkers, for example due to poor

the building had been evacuatedsearch and rescue applications.’‘I believe if robots had been used tomake a risk assessment first, thistragic ending could have changed
for a happy one.’15

fundament

AUTONOMOUS ROBOTS PROTECT THE LIVES OF EMERGENCY SERVICES IN DISASTERS

Search and rescue robots should

the most important information tomathematical decision making andbecome autonomous

rescue workers to determine themodelling. One of the topics I am

One of the reasons that search andplaces they need to go to or should

currently working on is systematic

rescue robots are not always usedavoid.’

incorporation of uncertainties inis that they cannot operate fully

AUTONOMOUS AND SELF-LEARNING CONTROL SYSTEMS‘People with autism find it
difficult to make contact withothers. It is often easier forthem to communicate withsocial robots.’mathematical and model-based

autonomously, says Jamshidnejad.

Mathematical decision-making

decision making: How can a robot‘Drones do not yet have fullyand AI: breakthrough in next gen

or a drone operate autonomously

autonomous decision-making

robotswhen confronted by various

capabilities. Human assistanceAt the time of the ﬁre in Teheran,random, vague and unpredictable

is still needed to operate the

Jamshidnejad was ﬁnishing thesituations? We also want drones todrones and to determine whatlast months of her PhD studies.

use a combination of optimization

actions they should perform. You

After obtaining her PhD, sheand AI to learn from thesecan pre-programme them withdecided to follow up a postdoctoralsituations to recognise danger andinformation about a building or

research position at the Institutelocate victims or hazards.’

area, but during a disaster thefor Dynamic Systems and Control

situation changes. Uncertainties

at ETH Zurich. In February 2019,

Minimizing use of powersuch as blockages from collapsed

she returned to the Netherlands‘Search and rescue robots

walls or unpredicted spread of ﬁreto continue her research in Delft.

analyze and transfer the datamean that the initial ﬂoor plans or‘I had already done my PhD at TU

they gather to the rescue

maps of the area may no longer

Delft, so I had an extensive network

team outside the disasterbe accurate. This is particularlyof researchers in the Systems,

scene in real time’, continues

where search and rescue robots

Control & Simulation research

Jamshidnejad. ‘It is crucial thatcan make a difference: they cangroups. Besides this, at TU Delft

no important information is lost

independently go into the unknown

there is extensive expertise in

if a drone suddenly becomes

area, plan a mission and start

the ﬁeld of artiﬁcial intelligenceout of function’. Most drones

to search and assess the new(AI), which dovetails well with myare ﬁtted with a camera but insituation. Then they can transfer

own theoretical background in

extreme circumstances the images

ANAHITA
JAMSHIDNEJAD
Assistant Professor
Mathematical
Decision Making

16

aerospace

they send may not be useful,scenarios that are similar to real-robots is not only useful in searchfor example due to darkness orlife search and rescue missions

and rescue’, says Jamshidnejad.

smoke. Or sometimes a camerain the lab. This way we canThere are also valuable healthcare

may fail. Therefore, often several

perform experiments to assess

applications, such as therapeuticrobots and drones are deployed atand improve the performance ofaids for people with autism oronce. One or a few of them receive

our robots. Moreover, in the end

dementia. Jamshidnejad: ‘People

the most important data of the

our robots should collaborate

with autism ﬁnd it diﬃcult to maketeam when one is lost. ‘It takes aand communicate with real ﬁrecontact with others. It is often

lot of power to process all the data,

ﬁghters.

easier for them to communicate

so we need to develop an optimal

with social robots, in part because

approach that minimizes the use

Therefore, close collaborations andof the robot’s predictability andof power, as well as the missioninteractions with ﬁre departments

lack of emotions. For the ﬁrst

time’.

from the very ﬁrst stages oftime, we are introducing social

implementations of the projectdrones that engage in dance

Next: Collaboration with fire

are necessary. Another importanttherapy. We want to further

servicespartner in this research is Thales,

improve robots, so that when

Jamshidnejad plans to use model-

a company that specialises inthey are in interaction with people

based and knowledge-based

drone technology, among otherwith autism or dementia they cancontrol methods based on theaerospace applications. Thales

assess situations independently

expertise of experienced rescue

is helping us with the further

and act based on a personalized

workers, such as the Dutch ﬁredevelopment of well-functioning

and creative plan. In summary,departments. ‘Fire brigades know

search and rescue robots.’

my research has a wide range of

all the aspects associated with aapplications. I think it’s really great

disaster and the dangers involved.

More applications forthat I can now use my theoretical

We can use their expertise andautonomous robots

background to help solving real-life

information on disasters and‘Improving the autonomy andproblems.’

emergency situations to simulateeﬃciency of decision making by

17

fundament

civil

GETTING IT STRAIGHT: BRIDGES ARE BECOMING CIRCULAR

MATERIALS & ENVIRONMENT

Getting it straight:

Bridges are
becoming circular

A large number of bridges in the Netherlands are scheduled forlarge-scale maintenance work or replacement. In order to minimise
the effect on the environment and bring down costs researcher
Wenjun Cao is working on a model to assess the potential for
circularity of these bridges. This will help the Netherlands toachieve its aim of a fully Circular Economy (CE) by 2050.

Circular champion

Advantages for the Netherlands

comes to separating the materials of a

Cao came to Delft in June 2020. ‘I wanted

Circular building has many advantages,

bridge component, grinding it down and

The importance of good infrastructure

to do more research into the potential

Cao says. ‘Less production of steel andusing it to produce something new. We

Cao became fascinated by bridges

for circularity in civil infrastructures. The

concrete will lower CO2 emissions.

can skip that step if the components

when she was a little girl living in China.

replacement brief and the developments

Recycling the way it is done now ishave the potential to be used in a new‘I grew up in a small city in the north ofin circular building make the Netherlands

energy intensive, particularly when it

construction, for example.

Shanghai. In order to get to the big city

an interesting country. However, reuse

we would have to cross the Yangtze riverof infrastructure has remained relatively

Railway bridges, drawbridges, ﬂy-overs,‘Much of the Dutch infrastructure dates

by ferry. In 2008, with the opening ofunderresearched. Bits of bridges or

sluice bridges: the Netherlands leaves thefrom the post-World War Two period,

Sutong Bridge, the transportation timeroads are being recycled here andrest of the world standing when it comes

as is the case in many other Western

between cities has been cut down fromthere but it’s not happening in a very

to the number of bridges per square

European countries. A concrete or steel

three hours to one hour. That’s when I

eﬃcient way. What is needed is akilometre. The exact number is not

structure has a life span of at least 50

ﬁrst understood the importance of goodcomprehensive approach. It is my aim to

known but the water authorities alone are-100 years. But traﬃc has intensiﬁed overinfrastructure and the value of bridges. It

set up a framework in which circularity is

managing over a thousand. Many of thethe years and maintenance work has toprompted me to study Civil Engineering in

integrated into the design, construction,

bridges are approaching the end of their

be carried more frequently. Quite a few

China. Following my graduation, I went on

operation, maintenance and dismantlinglife cycle, says Wenjun Cao, assistantbridges will have to be partly or entirely

to work as a bridge engineer for ﬁve years

of infrastructure, starting with bridges.’

professor Engineering Structures at CEG.

replaced in the next couple of years.’and did a PhD in Singapore.’18

ʻIt is my aim to set up a frameworkin which circularity is integrated
into the design, construction,
operation, maintenance anddismantling of infrastructure.ʼ
19

fundament

GETTING IT STRAIGHT: BRIDGES ARE BECOMING CIRCULAR

civil

MATERIALS & ENVIRONMENTʻThe big challenge
is to chart thecircularity
potential of thethousands ofbridges of theNetherlands.ʼ

ʻEvery bridge will be given acircularity label, similar to the energy
labels for homes. According to thelabel a bridge or a component is ﬁt for
repair, reuse, rebuild or recycling.ʼ

Eﬃcient reuse of bridges can help the Netherlands achievea relatively new phenomenon too. In that case it is important

climate and circular economy goals. And what’s more, it pays.

to check if the structural behaviors of the components are

According to my calculations, assuming the average cost saving

suited to the conditions surrounding the new bridge. If metal

through circular strategies is 5% - 15%, with every 1% of thecomponents are used in a bridge standing in water with a higher

road sector adopting the recommended strategy, the potential

salt content they had better be corrosion proof.’

market we are dealing with is worth $15- 53 billion from 2016 to
2040. The Netherlands could become a circular building pioneer

Artificial Intelligenceand export its knowledge to other countries such as Germany

The big challenge is to chart the thousands of bridges inand France which are facing similar infrastructure challenges.’

the Netherlands. To study every single bridge in detail in the
traditional way is neither viable nor necessary, Cao says. ‘For

Circularity label

the collection of data we will be turning to AI. Sensors andCao’s research is focused on the circularity potential of bridges.

drones can help us study bridges in great detail. We thenThat means she will be studying the current state of the bridges,

combine these data with the information we have on the age

the materials used to build them and the environment in whichof the bridge, the structural type and material behaviour. Basedthey are situated. Cao: ‘Based on this information we canon the data analysis every bridge is then provided with its

estimate which parts of the bridge can be reused or repaired

own circularity label. So I will be working very closely with AI

and how to go about it. Every bridge will be given a circularity

specialists.’

label, similar to the energy labels for homes. Depending on theassessment, a bridge or a component can be labelled ﬁt for

Information sharing platform

repair, reuse, rebuild or recycling.’

Cao’s aim is to develop a platform for (local) authorities andbusinesses to share information about ways to include bridges

Reuse of existing infrastructurein the Circular Economy. Cao: ‘In order to achieve optimal

Changing the purpose of a structure is a particularly

circularity cooperation throughout the chain is crucial. Smartrevolutionary approach, Cao says. ‘It has been happening a lot

design can help to eﬃciently take apart components andwith buildings lately. An old factory is turned into a restaurant,

reuse the materials of bridges. With smart design and modular

for instance. The same can be done with infrastructure. A bridgebuilding, you can dismantle a bridge as easily as if it were madethat is no longer ﬁt to carry heavy traﬃc can be repurposed asof Lego. And not just bridges but other types of infrastructure

a pedestrian bridge. Rebuild, or using components of a bridge

as well, such as roads and railways. That shows the potential ofthat has become superﬂuous to build another in the area, isthis research.’

20

WENJUN CAO
Assistant Professor
Engineering
Structures at CEG

21

fundament

INTERVIEW

L.T.R: HANS HELLENDOORN, LINA SARRO, GUIDO DE CROON AND BERT SLUYS‘we should havedone this earlier’To begin with, what exactly do the Sector Plans

But these funds didnʼt come without strings attached.

entail again?

How was that received?

Sluys: The idea is to highlight certain ﬁelds ofHellendoorn: As a faculty, we were forced to thinkstudy which have been somewhat overlooked inabout our focus areas. Thatʼs not something we

recent years because of their more fundamental

would have done on our own volition, but it wascomponent. For us, this means a signiﬁcant

extremely helpful.

strengthening of staﬀ. A unique opportunity andan extremely important contribution to education
and research, also in the long term. Our groups
have been able to attract top scientiﬁc talents who

For TU Delft, the engineering Sector Plans represent the reinforcement of
21 priority areas spread across four faculties. How do four leaders in thesepriority areas, one from each faculty, look back on the implementation of

De Croon: The same applies to us. Aviation isfacing major challenges, and thatʼs also putting

the plans thus far? The day after the announcement of a new coronavirus

considerable pressure on our education. Issues

lockdown, professor Lina Sarro (EEMCS), professor Bert Sluys (CEG),

such as sustainable aviation and autonomousWhy?

drones are booming; society urgently needs

Hellendoorn: Mechanical engineering is an oldengineers trained in these ﬁelds. The Sector

discipline. Millions of years ago, people werePlans oﬀer scope to strengthen these disciplines,

already making tools. Since then, the discipline

including education. Itʼs going to have a

has grown in all kinds of ways. The Sector Plans

considerable impact, Iʼm convinced of that.

forced us to ask ourselves: who does what and why?

professor Guido de Croon (AE) and professor Hans Hellendoorn (3mE)
met digitally to discuss this issue.

22

would otherwise not have come.

ʻAVIATION IS FACING
MAJOR CHALLENGES, AND
THATʼS ALSO PUTTINGCONSIDERABLE PRESSURE
ON OUR EDUCATIONʼ

23

fundament

INTERVIEW

Sluys: This coordination has also taken

De Croon: We didnʼt hire our new female

place nationally. We sat down with our

staﬀ members because theyʼre women.

colleagues from Twente and Eindhoven,

They were without doubt the best

which was a positive step. We have tocandidates.

continue working together, even though
the positions have already been allocated

De Croon: Thatʼs not easy to deﬁne. You
There were also requirements regarding

have to look at expertise, research results

the distribution of positions to males andand teaching skills, for example. ThereGUIDO DE CROON

females.

Professor ʻBio-inspired
Micro Air Vehiclesʼ(faculty of AE)

are many factors to consider. Itʼs not an

Hellendoorn: The fact that a third of theobjective calculation that a computer

positions should be occupied by women

could make as well.

was a tough requirement. Thatʼs beena tremendous help. In fact, I would

Hellendoorn: Ultimately, itʼs decided by arecommend it to everyone.

committee that has a certain idea of whatthe ʻbestʼ candidate is. And sometimes
you have to force a committee to brieﬂyrenounce their traditional way of
thinking.
How did the search to ﬁll the Sector Plan

Surely, the sectoral plans werenʼt so
unusual in that respect? Focusing on
gender balance is pretty much universal
now, isn't it?

Sarro: Focusing on something isnʼt thesame as making it compulsory.
LINA SARRO
Professor Electronic Components,
Technology and Materials (ECTM)
at the department of Microelectronics(faculty of EEMCS)

Hellendoorn: Weʼre a somewhat older
faculty, and we still had groups thatdidnʼt employ a single female researcher.
I think that women are inherently at a
bit of a disadvantage there. But thesegroups had no choice. I have seen with
my own eyes how the atmosphere there
has changed. Weʼve brought in excellent
women, who immediately won a Veni
grant from NWO.
Sarro: But thatʼs how it should always be.

positions go?

Hellendoorn: It wasnʼt always easy. For
example, we had to ﬁll a position for
professor. Thatʼs extremely tricky in ourﬁeld. We searched endlessly and ﬁnally
hired a promising associate professor.
Sluys: We actively searched and evenenlisted a recruitment agency. But then
you ﬁnd people who have a diﬀerent
motivation than the candidates who arelooking for you.
Sarro: Thereʼs a strong competition forgood candidates. And sometimes youcome across a fantastic candidate who
doesnʼt ﬁt the proﬁle you have in mind.
Hellendoorn: Sometimes you have to
use a hammer to make the piece of theHellendoorn: Thatʼs true. But if thishelps…

24

Professor Computational
Mechanics (faculty of CEG)

Hellendoorn: What is the ʻbestʼ candidate?

and are being ﬁlled.

ʻFOCUSING ON SOMETHING ISNʼT THE
SAME AS MAKING IT COMPULSORY.ʼ

ʻITʼS IMPORTANT FOR TENURE TRACKRESEARCHERS TO START THEIRRESEARCH WORK AS SOON AS POSSIBLE.ʼ

BERT SLUYS

puzzle ﬁt.

Sarro: Itʼs a human process, and the

Theyʼre looking to interact with students.

larger result is what counts: enhancing

We have to be careful not to put too

research and teaching.

much on their plates too quickly.

Is this enhancement noticeable yet?

Has the foundation of the engineering

Hellendoorn: Itʼs already having a positive

sciences been suﬃciently reinforced now?

eﬀect for us. Our new staﬀ members

Hellendoorn: I donʼt want to soundare already teaching and supervisinggreedy, but weʼre not there yet. Our

students, which immediately reduces thestudent-staﬀ ratio was 40:1. Thanks topressure on the rest of the staﬀ. We canthe Sector Plans, thatʼs been reduced to

now spread our 100 graduates across 21

34:1, but thatʼs still far from ideal. Weʼve

instead of 17 staﬀ members.

grown tremendously in recent years; thisis overdue maintenance.

Sarro: The pandemic hasnʼt made it any
easier for new researchers to start their

De Croon: Students studying engineeringwork. Some only know Delft throughneed to be closely supervised, andZoom. So I donʼt expect to see the eﬀects

complex equipment has to be set up ﬁrst.

for another year.
Sarro: I would like to emphasise this:
De Croon: On the one hand, the workload

engineering studies are all about the long

has been reduced, but on the other hand,term. Thatʼs why I see the engineeringIʼve spent a great deal of time ﬁnding

Sector Plan as a kind of appreciation andcandidates for these positions. So forrecognition by the government that weme itʼs been a little bit busier. But I lovewonʼt get anywhere with proper funding.

PROF. DR. IR. HANSHELLENDOORN
Department Head Cognitive
Robotics (faculty of 3mE)

doing it, because I know that in time
weʼll really beneﬁt.

Hellendoorn: After the previous
economic crisis, there was an enormous

Sluys: Itʼs important for tenure track

increase in the number of students

researchers to start their research workin engineering studies. As a result ofas soon as possible. Teaching gradually

COVID-19, weʼre once again in thecomes into play after that. In terms

middle of a crisis. Who knows, itʼsof teaching, I expect a lot from them:conceivable that many more students

theyʼve been partly selected for theirwill opt for engineering again.

teaching qualities.
Sarro: Thatʼs why I believe we should
Sarro: These new colleagues really likehave developed the Sector Plans sooner

teaching too! Thatʼs why they chose to

and in more detail.

ʻSOMETIMES YOUHAVE TO USE
A HAMMER TO
MAKE THE PIECEOF THE PUZZLE
FIT.ʼ

work at a university and not a company.
25

fundament

FUTURE RESEARCH

futureresearch

SUSTAINABLE DESIGN AND
MANUFACTURING OF MATERIALSʻI will conduct research on the recyclingof hybrid and complex materials. This
will include developing recycling routes
for existing structures and materials thatare currently diﬃcult to recycle, as wellas collaborating with colleagues who aredesigning and building future materials
on ʻdesign for recyclabilityʼ. Initially,
I will investigate the recycling of highperformance thermoset composites that areused for structural components in aviationand transport and looking into the reuse
and repurposing options for wind turbine
blades. In the near future, I plan to expand
to diﬀerent types of material combinations,
including batteries, waste electrical andelectronic equipment, and multilayer
packaging ﬁlms.ʼ

DIGITAL POWER SYSTEMSʻI will conduct research on nonlinear
controlling methods for hybrid power systems.
The hybrid power system presents an AC
power system interconnected with a High
Voltage DC-based power system throughpower converters. The hybrid power systemis the system of the future. My ongoing
research is to design new controls and test thesystemʼs stability after the application of thecontrolling method.ʼ

SID KUMARSUSTAINABLE DESIGN AND MANUFACTURING
OF MATERIALSʻI will conduct research on physics- and data-driven
computational methods for understanding the mechanics andphysics of complex materials and structures – including metals,
polymers, composites and architected metamaterials, as wellas their manufacturing, such as thermomechanical processing
and additive manufacturing. Contrary to the traditional
approaches in materials by design – based on exhaustive
simulations and experiments, computational design by datadriven and machine learning methods is the new frontierthat oﬀers quick identiﬁcation and reduction of the design
space, eventually leading to a faster turnaround of material
production that meets the requirements. To this end, I will work
towards the paradigm of the inverse design of materials where
the challenge is to systematically and eﬃciently reverse engineer
material designs and processing techniques to achieve tailored
and/or extreme properties and functionalities.ʼ

MATIN JAFARIAN
DATA-DRIVEN MODELLING AND CONTROLKSANDER DE WINKEL
HUMAN-ROBOT INTERACTIONʻI will conduct research on motion sickness. According to the most prominent theory,
motion sickness results from something called sensory conﬂict. This conﬂict represents a
discrepancy between motion that our senses signal and motions we expect based on aninternal predictive model. However, it is uncertain what this conﬂict really is. Present
models represent it in diﬀerent ways, and they are only partially successful in actually
predicting motion sickness. In my research, I hope to improve our understanding of whatmotion sickness is by ﬁnding ways to detect early signals of motion sickness; by exploringnew modeling techniques; and by accounting for individual diﬀerences in susceptibility.ʼ
ʻThe outcome of my research will enhance the comfort of traveling, in particular in thecontext of automated vehicles. By maximising comfort and minimising the chances of
motion sickness, we will make sure that we can use the full potential of this new technology:
freeing up time to engage in activities other than driving, improving fuel economy andreducing the risk of accidents. This will beneﬁt not only the individual, but society as awhole.ʼ

26

The spotlight in this Fundament magazine is on 15
researchers who have been working on their research at
TU Delft for some time. But positions are still being ﬁlled
and so new researchers are starting each month. Who are
our newest talents and what will they be focussing on?

ʻThe outcome of my research will contribute tosociety and the environment by improving thecircularity and sustainability of materials.
This is a diﬃcult task, as materials andstructures are becoming more multifunctional, requiring complex combinationsof materials and elements, but I am conﬁdent
that we will be able to make a positive shift,
as this issue is receiving more and more
attention from society, as well as government
and industry.ʼ

ALEKSANDRA LEKIĆ

ʻThe outcome of my research will contributeto the decarbonization of the power system.
Application of new control methods into a
hybrid power system will ensure its stability,
together with faster convergence and recovery
from faults. Research results will include theimplementation of the multi-vendor control
for hybrid power.ʼ

SHOSHAN ABRAHAMI

ʻI will conduct research on the modelling, analysis, andcontrol of complex biological networks with applications
in both the engineering and health domains. My
main research focus is modelling, analysis and theregulation of biological brain networks underlying
human cognition, in particular memory, learning anddecision-making. The importance of the mechanistic
understanding of human cognition emerges from its
central role in our health as well as being a main sourceof inspiration for addressing the need for active model
learning and adaptive capabilities of future engineeringsystems.ʼ

ʻThe outcome of my research will contribute to a diverse suite ofapplications in materials. For example, my research on process
design for sustainable production of metals will focus on
improving the strength and durability of high-demand metals
such as copper to mitigate the rapid depletion of natural ores,
and pushing forward the viability of alternative metals suchas magnesium for industrial and commercial products. My
research on inverse-designed bio-mimetic metamaterials will
focus on applications in personalised biomechanical implants –e.g. synthetic bone substitute that locally matches the propertiesof the natural bone for improving long-term compatibility andpreventing bone atrophy. Other applications of my research
include energy-absorbing composites, acoustic metamaterials,
data-driven constitutive modelling and multiscale modelling ofadditive manufacturing processes.ʼ

ʻThe outcome of my research will contribute to novel
medical and therapeutic methods in the area of humanmemory functioning as well as advanced solutions for
future adaptive engineering systems. I will develop
models using both knowledge-based and data-driven
approaches, and utilise tools and techniques fromdynamical systems and control theory, in particular
nonlinear, discontinuous, hybrid and stochastic
dynamical systems.ʼ

27

fundament

USING SMART TECHNOLOGY TO MAKE FUEL OUT OF CO 2

mechanical

MULTIPHASE FLOW FOR LOW-CARBON SYSTEMSʻAfter capturing CO₂ fromthe air, I want to makefuel out of it, which can beused to run machinery infactories and to power cars
and so on, as a renewableenergy sourceʼ

using smart
technology
to make fuelout of co2
Too much CO₂ in the air is currently causing a major problem:
climate change. If it were up to Peyman Taheri, researcher atMaterials Science and Engineering at TU Delft, we would be making
smart use of surplus CO₂ by converting it into a new fuel. A fuel that
could power factories and send cars hurtling down the motorway.

28

29

fundament

USING SMART TECHNOLOGY TO MAKE FUEL OUT OF CO 2

One of the main causes of climate change is theTaheri studies different materials, including

huge amount of CO2 released into the air every day.

nanomaterials, metals and semiconductors. ‘First I

It’s emitted by cars, power stations and factories, formanufacture them, and then I examine their properties

example. These large quantities are heating the earth

and tune them towards an eﬃcienct fuel production

up, melting (polar) ice and threatening to cause theprocess. It’s important to completely master thesea level to rise at an alarming rate. This is a worrying

material properties. Only then you can really get thedevelopment, according to TU Delft scientist Peyman

most out of this material.’

Taheri.
Valuable fuelHe’s therefore working with colleagues to ﬁnd a

The end result should be the fuel, and if all goessolution. They want to capture CO2 from the air, so it

well, soon you should be able to ﬁll your car withcan no longer contribute to the climate change.

it on the motorway. Imagine speeding down the
highway on fuel that not only drives you forward‘After CO2 has been captured,’ Taheri adds, ‘I want to

but is also based on CO2, which is causing so much

make fuel out of it that can be used to run machineryinconvenience right now. It’s not clear yet whether

in factories and to power cars and so on, as aﬁlling up your car will become much more expensive.

renewable energy source’.

‘That remains to be seen, but I think we can makethis new fuel competitive,’ the materials expert says.

That’s quite a turnaround. Instead of emissions that

‘Making it available for exactly the same price won’t behave highly detrimental consequences, this approachnecessary in the near future, because this fuel does soturns a problem into something that you can actuallymuch more as it also removes CO2 from the air. Thatbe used and has added value.

gives it added valuable.’mechanical

MULTIPHASE FLOW FOR LOW-CARBON SYSTEMS

ʻI do a lot of experiments.
Sometimes I also test things
that I donʼt quite understandyet. I always start by analyzing
what the properties of materials
are and whether they havethe right composition to turnCO₂ into a fuel.ʼ

Taheri believes that in the near future CO2 won’t only
Getting everything out of materials

serve as fuel for cars, but will also be captured rightTaheri is still looking for a smart way to convert CO2

next to factories. ‘Researchers are already working on

effectively into a synthetic fuel. ‘That’s not so easy

devices that do this. It will then be possible to convert

from a chemical point of view, because CO2 consists

the captured CO2 into energy, which will supply theof very strong bonds. So you need something that canplant with electricity. Scientists are already working on

break those bonds.’

this.’
It’s a tempting prospect that really motivates Taheri.

To do that, Taheri is working on so-called‘Climate change concerns me, and I want to doelectrocatalyst materials converting CO2 into synthetic

something about it. I hope we’ll ﬁnd an increasing

fuels through electrochemical processes. This makes

number of affordable, green solutions in the future. It

it possible to break the solid molecular compounds

would be great if we could eventually create a negativeand make fuel out of them. ‘We’re manufacturinglevel of CO2 in the air, so that more CO2 is taken out

a new material for that purpose, which must haveof the air than is emitted into it. That will really help

the right properties,’ the scientist says. ‘I do a lot of

reduce levels. My research will hopefully contribute toexperiments. Sometimes I also test things that I don’t

that. I think it’s my responsibility as an engineer andquite understand yet. I always start by analyzing what

scientist not to stand on the sidelines, but to roll up

the properties of materials are and whether they havemy sleeves and use my energy and knowledge to solve

the right composition to turn CO2 into a fuel.’

the CO2 problem.’

30

PEYMAN TAHERIAssistant Professor
at the departmentof Materials Scienceand Engineering31

fundament

FILLING THE GAP: TERAHERTZ WAVES FOR NEXT GENERATION SENSING AND COMMUNICATION

electrical

MICROELECTRONICS

The much higher datatransfer rates of beyond5G technology will allow
an entire soccer stadium
Developing technology for the terahertz region of
the electromagnetic spectrum used to be a very
expensive hobby, only pursued by space exploration

to live-stream the matchin Full HD.

scientists and the military. Maria Alonso-delPino
uses advances in silicon chip technology to open up
a whole universe of more worldly applications –enjoying the fundamental challenges that still need
to be addressed.
In our daily lives, we are surrounded by technology utilizing
microwaves and visible light. Think of Wi-Fi and and yourmicrowave oven and, for visible light, your ﬂat screen TV and cell
phone camera. Falling right in between microwaves and visible
light, the terahertz frequency band still faces many technologicallimitations that prevent its wide-spread application. Sources ofthis radiation are not powerful enough, detectors not sensitive
enough and either of them not compact enough. ‘It has led towhat is called the terahertz technology gap,’ says Maria Alonso-

Filling the gap:

Terahertz waves fornext generation sensing
and communicationdelPino. ‘Over the last few years, however, cheap and mass
producible silicon technology has opened up new applications
for terahertz radiation; autonomous cars, medical imaging, everfaster wireless communications, anything that was not viable
previously because of cost.’
As an assistant professor in the Terahertz Sensing group at
the Department of Microelectronics, she uses her expertise inelectromagnetics and system design to help ﬁll this terahertz
technology gap. ‘I enjoy being involved in the very early stages ofthese breakthrough developments,’ she says. ‘I closely collaborate
with researchers from the electronics group and other disciplines
to build proof-of-concepts of solutions that can beneﬁt society as
a whole.’32

33

fundamentelectrical

FILLING THE GAP: TERAHERTZ WAVES FOR NEXT GENERATION SENSING AND COMMUNICATIONTERAHERTZ RADIATION
One terahertz (1 THz) equals
a thousand billion oscillations
per second. Radiation in
the terahertz region of theelectromagnetic spectrum has
frequencies of 0.3 to 20 terahertz.

MICROELECTRONICS

x-rays and infrared radiation. But x-rays are ionizing

Delft resulted in a single pixel, created using standard

and therefore potentially harmful. And, comparedsilicon chip technology. Right now, we want to taketo infrared imaging, terahertz radiation has thethe ﬁrst images, using a mannequin. Our ultimate goal

advantage that it can easily pass through certain

is for the camera to have a thousand pixels, allowing

materials, including clothes and even the ﬁrst layers

very fast thermal imaging through objects.’of the skin. This makes it very suitable for security
applications and for certain medical diagnostics.

A little wait

‘Microwaves can pass through materials evenOnce new technology has become a part of our daily

more easily,’ Maria Alonso-delPino says, ‘but theirlives, it is easy to forget that its development tookmuch larger wavelength means that you lose out insome time. But digital cameras didn’t arrive overnight,

resolution. Terahertz is the compromise between

and it took twenty years to build a microwave ovenresolution and transparency.’ Put simply, a doctorthat was affordable and that ﬁt into a kitchen. The

may not be able to properly identify a skin cancer

same holds true for terahertz technology. Afterit has to have low-powerwith pixels the size of a Tic Tac. Within the TiCam

proof-of-concept by Maria Alonso-delPino and her

consumption, low weight andproject, Maria Alonso-delPino and colleagues would

colleagues, industry needs to pick up on these ideas

like to build a high-resolution camera at terahertz

and develop them into fully ﬂedged products. It isfrequencies. One of the major challenges is for theimpossible to predict how long this will take. But

camera to have a high-enough sensitivity to image

when, at some future moment, you can live-stream

just the radiation emitted by a person or an object –Full-HD video from anywhere at anytime, you will know

meaning that it doesn’t require an external source forthat the terahertz technology gap has been closed.

The common theme for all
terahertz technology is thatbe small.

Diﬀerent applications, similar challenges

people with a good, or any signal. ‘We want to solve

In her research, Maria Alonso-delPino focusses on

this using what we call beyond-5G technology,’ she

the hardware side, designing high-frequency front-end

says. ‘In the Fly’s Eye Project, we use much higher

radiating systems and how these are interfaced to thefrequencies, allowing much higher data transfer rates

electronics that are further down the line. Many of theas well as a substantial reduction in radiated power.’

challenges she faced when designing state-of-the-art

At just over half a meter in diameter, the Fly’s Eyetechnology and instrumentation for space science atwill hang in the middle of the stadium, covered in

the NASA Jet Propulsion Laboratory still hold true.

passport-photo-sized ‘eyes’, much like the compound‘The common theme for all terahertz technology is

eye of a ﬂy. Each eye consists of a bunch of terahertz

that it has to have low-power consumption, low weighttransmitters, receivers and a lens – their wide-angle

and be small,’ she says. ‘But now it also has to be low

beams overlapping to cover the entire stadium. ‘I am

cost and preferably have new capabilities such asbuilding the antenna-systems for each of these little

the ability to handle multiple frequencies and be ableeyes,’ Maria Alonso-delPino says. ‘We also have toto steer the radiated beam. And, it should preferably

make it into an integrated and scalable system. Ourconsist of multiple pixels.’goal, in a few years’ time, is to demonstrate a proof-of-

illumination. Maria Alonso-delPino: ‘Initial steps at TU

MARIA ALONSO-DELPINO
Assistant Professor Terahertz
Sensing (THZ)

concept in the TU Delft Aula.’
Beyond-5G

34

One area where Maria Alonso-delPino is eager toUnder your skinapply her skills and let terahertz technology shine

Imaging is another application where terahertz

is wireless communication. Especially in crowded

radiation may be able to outshine, or at the least

places – a soccer stadium or an open-air festival

complement, existing technology. When it comes

accommodating tens of thousands of people – theto imaging outside of the visible spectrum, we, as

much-hyped 5G will never be able to provide mosta society, are already quite familiar with the use of

Terahertz technology no longer is a very
expensive hobby, only pursued by space
exploration scientists and the military.
35

fundament

civil

HELP FROM ON HIGH TO SOLVE EARTHLY PROBLEMS

SOIL MECHANICS

help from on highto solve earthly
problems
The ground beneath our feet isconstantly moving and that cancompromise the stability of buildings
and infrastructure. Satellite data arehelping Giorgia Giardina to chart
the impact of subsurface activity on
buildings in great detail so eﬃcientmeasures to limit damage, cost and‘Based on a better
understandingof what happens
underground I
try to determine
the vulnerabilityof a building andthe extent of any
damage that may
occur.’

safety risks can be taken before itʼs
too late.
Some parts of the Netherlands are sinking andnone faster than the west and northeast of thecountry, where groundwater level decline andgas extraction are among the main culprits.
And what happens below ground often aﬀects
what is happening on the surface, says assistantprofessor Geo-monitoring and Data Analytics
Giorgia Giardina. ʻSubsurface activity, such as
ground subsidence, tunneling or earthquakes,
poses a risk to surface buildings. Urban areas inparticular can be badly aﬀected, with buildings
suﬀering severe subsidence and cracks. Without
proper measures the damage to homes and

GIORGIAGIARDINA
Assistant Professor
Geo-monitoring andData Analytics

other buildings will run into billions of euros
in the years ahead. Peopleʼs safety could also becompromised.ʼ
36

37

fundament

civil

HELP FROM ON HIGH TO SOLVE EARTHLY PROBLEMS

SOIL MECHANICS

Below and above ground interaction

so many challenges in terms of subsidence andactivity you can take precautionary measures inWith a background in both environmental andmaintenance of infrastructure and buildings.

vulnerable areas, such as re-enforcing the soil orcivil engineering Giardinaʼs area of expertise is

Many Dutch bridges are nearing the end of theira building. Thanks to the satellite data you canwhere above and below surface activities meet.

life cycle and Groningen province is having toalso monitor movement during construction soʻThe interaction between what we can and cannot

cope with a lot of damage to homes because ofmeasures can be taken in time.ʼ

see has always interested me. Plus Iʼm from Italy,

earthquakes. Our Dutch ﬁndings will help othera country with a great many heritage buildings

countries with similar problems as well. Insights

and a relatively high number of earthquakes.

from the work on the North South metro line

Based on a better understanding of what happens

are now being used in the construction of thesatellite imaging could

underground I try to determine the vulnerability

Crossrail project in London, for example.ʼ

detect movement in

may occur. For my Masterʼs I worked on a risk

Damage assessment systemevaluation of historical buildings in Italy. I then

At TU Delft Giardinaʼs job is to devise a method to

did my PhD in Delft, about the eﬀects of theassess the risks of subsurface activity. A damageof 600 kilometres withexcavation work on the North South metro line inassessment system, she calls it. ʻItʼs a modelup to the millimetre

Amsterdam. I then went on to Cambridge to do awhich will enable us to estimate how a building

postdoc, and later started my own research groupwill react to certain subsurface developments

in Bath.

and where damage may occur. To do this we‘my eureka moment:
when i discovered thatbuildings from a height

accuracy.’of a building and the extent of any damage thatcollect diﬀerent types of data. Apart from theHelp from on highsatellite data we need information about theDuring her time at Bath Giardina spent much of

behaviour of buildings and bridges. Concrete

her time working with space agency NASA. Her

structures will react diﬀerently to subsidence

Eureka moment came when she was talking tothan brick buildings. The stiﬀness of the material

one of the space scientists, Pietro Milillo. ʻHe told

plays a role as well. We also need to knowme that satellite imaging could detect movement

about the environment of the building, thingsin buildings from a height of 600 kilometres

like the surrounding infrastructure and thewith up to the millimetre accuracy. That was asubsurface conditions. The tricky bit is to selectPrevent deaths and save heritage buildings

fascinating piece of knowledge and very valuable

the most relevant data and integrate it into theGiardinaʼs work is not just about preventing

for the research I was doing. I had been using

model eﬃciently. The use of satellite data fordamage and saving money. ʻIt is, of course,

sensors to monitor individual buildings but now

applications in civil engineering, for instance, isalso very important in terms of human safety.

I could suddenly chart and study the movement

relatively new.ʼ

A collapsing building can result in manyof lots of buildings and infrastructure in a muchlarger area.ʼ

38‘I want to develop a damage
assessment system, to help
us estimate how a building willreact to certain subsurface
developments and where
damage may occur.’casualties. If it does happen, for instance after an
Setting priorities

earthquake, you want to be able to bring people to

A good predictive model will help prioritisesafety as quickly as possible. The satellite images

Subsidence, maintenance and replacement

what needs to happen in terms of maintenancecan visualise the damage and pinpoint the places

Last May Giardina decided to take up a post as

and replacement, Giardina says. ʻPolicy makers

for the emergency services to go, or to avoid asassistant professor at TU Delft. ʻDuring my time aswill have to decide which work should be done

the case may be. Timely maintenance plays an

a PhD in Delft I noticed how much knowledge isﬁrst. You canʼt do it all at once but if you know

important part where historical buildings areconcentrated here from diﬀerent disciplines suchwhere the problems are most acute youʼll know

concerned. Iʼm from a country steeped in history

as Geo-Engineering, Remote Sensing and Data

where to make a start. Timely interventions inand the Netherlands, too, is a treasure trove

Science. I need all of these ﬁelds of expertise forthe right spot will save a lot of time and money.

of historical buildings, just think of the canal

my research. Apart from that, the Netherlands is

The data will also help future building projects.

houses. I live in one myself in Delft. For that toan interesting place for study because itʼs facing

If you know how buildings react to subsurface

disappear doesnʼt bear thinking about.ʼ

39

fundament

IS HYDROGEN-POWERED AIR TRAVEL THE FUTURE?

aerospace

FLOW DYNAMICS FOR LOW-CARBON SYSTEMSIVAN LANGELLA
Assistant Professor
Sustainable Aircraft
Propulsion

Is hydrogen-powered
air travel the future?

Although the coronavirus has currently left many

Cleaner fuel, but there are risks

aircraft grounded, aviation is developing at a rapid

As an aerospace engineer specialised in ﬂuid

pace behind the scenes. Sustainability is one of

dynamics, Langella is playing an important role inthe main reasons why this is happening. Currently,

the development of hydrogen engines for aircraft.

aviation accounts for some three percent of global‘Hydrogen-powered cars have appeared in the market,

CO2 emissions, but with lack of alternative sources

but there’s not yet a hydrogen engine for aircraft that

this ﬁgure could go up to a quarter of the global
emissions in the next 3 decades. And this is without
including dangerous emissions such as nitric oxides.
There is thus much scope for progress within theʻWe may see quite diﬀerently
shaped airplanes in the sky inthe future than we are used to.ʼaviation industry when it comes to sustainability, says

Hydrogen is a sustainable alternative to kerosene-powered air
travel because there are no CO2 emissions. But hydrogen is also
associated with challenges and risks, such as the danger of
explosion. Ivan Langella aims to use mathematical models, highﬁdelity computational simulations and experiments to develop azero-emission hydrogen-powered engine that will enable aircraft
to ﬂy safely and eﬃciently.

40

Ivan Langella, Assistant Professor in SustainableAircraft Propulsion. ‘Existing kerosene-powered

works effectively. Much more research is needed

aircraft engines cause high levels of CO2 emissions

on what is feasible for aviation and how engines

and pollution. If we want to combat further climateof this kind can be eﬃciently applied on aircraft,change, aviation will need to become much cleaner,

especially large ones. One of the key challenges is

especially if you take into account the ever-increasing

the instability of the ﬂame at some engine conditions.

number of ﬂight movements. One of the solutions that

This can lead to the ﬂame propagating towards the

could make a difference is the use of hydrogen. Thistank, a phenomenon known as ﬂame ﬂashback, andis because hydrogen combustion does not release any

consequently a signiﬁcant risk of explosion. So, we

carbon.’need to improve the engines reliability.
41

fundament

aerospace

IS HYDROGEN-POWERED AIR TRAVEL THE FUTURE?

FLOW DYNAMICS FOR LOW-CARBON SYSTEMS'Designing the hydrogen engine
as eﬃciently as possible in order
to integrate it into an aircraft is
another challenge.'

Despite the fact that a kilo of hydrogenobsessed by aircraft from an early age.

and KLM here, whose long term priorities

Impact on the environment,is three times more energetic than a kilo

On a fairground roundabout, I used toare still oriented for zero-emission ﬂights

society and knowledgeof kerosene, hydrogen requires muchlove sitting in the aeroplane, a passion I

despite the current suffering due to theLangella is enthusiastic about

larger tanks, even in liquid form. This

have nurtured in the adult age by taking

coronavirus.’

the idea that his research ismeans hydrogen-powered airplanes

ﬂight courses for small airplanes. I’mwould be larger than kerosene-powered

absolutely delighted that all of these

Perfect power and emission balanceof cleaner technology. ‘It does not

ones. The key will be to develop the

aspects and interests come together asWith his research group in Delft, Langellaonly matter for the environment,

hydrogen engine and storage tankpart of my job.’

is working on the development of a

but also for society as a whole.

hydrogen engine in various ways. ‘One

The quality of air and nature is very

without compromising on the weightcontributing to the development

ʻIʼm working on
mathematicalmodels andvery powerful
numerical
computations
in order toinvestigate
the behaviourin the engineʼ

and the aerodynamic eﬃciency of the

Plenty of expertise and partners

thing we’re investigating is how tomuch associated with the quality

aircraft, as this would mean more energy

Langella gained his Master’s instabilise the ﬂame in the combustionof human life. That means the

Several types of hydrogen engines

tanks and engines, and fuel transportneeded and thus more fuel consumption.

Aerospace Engineering in Italy, wherechamber. The combustion of hydrogen

research has an important social

What the hydrogen engine aircraft

will have to be arranged differently atThis implies we may see quite differently

he was born. He then completed a PhD

generates mainly water vapour but

value. Another interesting factor iswill ultimately look like is still

airﬁelds.’

shaped airplanes in the sky in the futurein Mechanical Engineering and held aalso nitrogen oxides (NOx). You needthat this technology also has thediﬃcult to say, according tothan we are used to.

post-doc fellowship in Cambridge. Next

to minimise these emissions as far as

potential for use in power plants,

Langella. ‘Several solutions are

Higher price, but environment takes

he was selected for the UK Excellence

possible, because NOx are damaging

addressing the world’s increasing

possible. We’re certainly not theprecedence

Complex processes within the gas

100 scheme and worked as Lecturer inin high concentrations. A relatively

energy demand in a sustainable

only researchers working on this.

Another important area of focus is theturbine engine

Thermoﬂuids Science and Engineering

new technology – known as lean-burnand clean way.

And in Delft we’re also focusing

way in which hydrogen is produced,

A gas turbine engine is made up of

at Loughborough University. He joined

technology – can allow this but often

on various subjects, including an

concludes Langella. ‘One method forseveral important components, explains

TU Delft as assistant professor lastresults in an unstable ﬂame as well.

The physical aspects underlying

engine that runs on a mixture of

producing hydrogen is from water

Langella. ‘We can broadly summarise

May. ‘TU Delft is one of the world’s

That’s why we’re aiming to strike the rightthe technology are similar,hydrogen and kerosene. Obviously,

via electrolysis. But that processthese in a compressor that compresses

leading universities in the ﬁeld ofbalance. I’m working on mathematical

although application in aircraft

it’s not completely emission-free,

itself also requires energy. If you use

and pre-heats the air from outside, theaerospace engineering. There is a lot ofmodels and very powerful numericalengines is slightly more

but will still contribute to reducing

fossil sources for that, you’re still notturbine that drives the compressor andknowledge here and the university offers

computations in order to investigate

complicated – as you cannot

an aircraft’s carbon footprint. Thatreally ﬂying sustainably. Designing

the combustion chamber in which fuelextensive opportunities for experiments,

the behaviour in the engine. Basedincrease weight in aircraft as easily

would be a great step forward

the hydrogen engine as eﬃciently as

and air are converted into energy. My

simulations and data processing using

on that, we can make assumptions

as you can in power plants. Thanks

in itself. An airplane mounting

possible in order to integrate it into

research focuses primarily on the latter.

powerful computers and top laboratories.

and predictions that we then test in

to strong investments in hydrogena hybrid engine could also be

an aircraft is another challenge. It’s

I’m fascinated by how ﬂuids interact and

The Netherlands is also at the forefront

experiments with a prototype. If an

research, the Netherlands anddeveloped more quickly, potentiallyhighly likely that hydrogen will provecan be exploited to deliver energy. Thesein the development of hydrogenassumption proves correct, we scale up

Delft University of Technology

within ﬁve to ten years. Using

to be a slightly more expensive fuelprocesses are especially complex intechnology. Not only industry, but also

the experiment. We’ll continue like thisare positioning themselves aan engine that runs completely

than kerosene, at least initially. But,

aircraft combustion engines and involve

the government is investing heavily in

until we have a stable and nearly 100%

step ahead to aﬃrm their role ofon hydrogen calls for major

in view of the advantages it delivers

a lot of physics and mathematics. But

clean-energy research. I’m able to do a lot

clean ﬂame. It’s very much a step-by-step

global leaders in both hydrogen

adaptations. Aircraft will need tofor people and the environment, that’s

that’s why I ﬁnd it so interesting. I’ve beenof work with aircraft manufacturer Airbus

process.’

technology and clean aviation’be equipped with different fuelsomething we’ll just have to accept.’42

43

fundament

FUTURE RESEARCH

futureresearch
The spotlight in this Fundament magazine is on 15
researchers who have been working on their research at
TU Delft for some time. But positions are still being ﬁlled
and so new researchers are starting each month. Who are
our newest talents and what will they be focussing on?

HANIEH BAZYARMULTIPHASE FLOW FOR LOW-CARBON SYSTEMS'I will conduct research on the development of the next generation“bio-based” membranes. Petroleum-based nonbiodegradable
polymers account for 95% of the total materials used formembrane fabrication. Considering the increasingly severeenergy crisis and environmental pollution problems, improving
the sustainability and promoting the green transformation of
the membrane technology is imperative. Apart from membrane
technology, I will also focus on investigating the other potential
application ﬁelds of bio-based polymers such as biomedical (e.g.
drug delivery) and sensing applications. This further requires
development of bio-based stimuli-responsive materials.

SIJUN DUAUTONOMOUS SENSOR SYSTEMSLAURA MARCHAL CRESPOHUMAN-ROBOT INTERACTIONʻI will conduct research on the general areas of humanmachine interfaces and biological learning and inparticular the use of robotic devices and virtual reality(VR) for the diagnosis, treatment and rehabilitationof neurological patients. My research interests are at
the intersection of engineering and neuroscience, andI investigate neurological phenomena using crossdisciplinary approaches from both domains. A major
goal of my research is to gain a better understandingof the underlying mechanisms associated with theacquisition of novel motor skills to develop innovativetechnology to improve neurorehabilitation.ʼ

ʻThe outcome of my research will contribute to making
electronic systems fully autonomous and self-sustained. With
energy harvesting, patients donʼt have to take surgeries for
replacing batteries in biomedical implants; wireless sensors
can operate continuously and independently; we donʼt have tocharge our smartphones or smart bands every a few days andsmart cities can be truly smart without periodically charging
or replacing batteries in millions of devices.ʼ

DIMITRIS BOSKOSDATA-DRIVEN MODELLING AND CONTROLʻI will conduct research on robust uncertainty quantiﬁcation and its applications
to data-driven control. My motivation comes from problems that entail dynamic
random elements about which the designer seeks to make inferences using a limited
amount of data, which is typically gathered online and may only reveal partialstate information of the process. I am therefore interested in leveraging results fromstate estimation and uncertainty quantiﬁcation to fuse information from both
the data and the system dynamics and obtain reliable uncertainty descriptions for
decisions and control.ʼ
ʻThe outcome of my research will contribute to the development of methods andalgorithms that account for environmental and model uncertainty, computational
tractability, and system constraints, and will ﬁnd applications in domains suchas robotics, energy and transportation. To this end, I aim to integrate tools fromﬁltering, adaptive control, nonparametric statistics and robust optimisation.ʼ

ʻThe outcome of my research will enhance the recovery ofbrain-injured patients. I aim to transform robotics and
VR into eﬀective and standardised tools in healthcarethat can be found ubiquitously and used eﬀectively
with minimum training and to maximum eﬀect. I willdevelop cutting-edge technology – e.g., immersive VR,
robotic devices and controllers, and hybrid AI – torecord, analyse, adapt and respond to usersʼ motor,
sensory and cognitive needs to maximise learning.ʼ

ANDRES HUNTADVANCED MATERIALS FOR EXTREME CONDITIONS

The outcome of my research will contribute to the developmentof a sustainable cycle in which bio-based polymeric materials,
derived from waste (e.g. wastewater or organic waste), can beused in separation applications such as wastewater treatment.
This approach can also contribute in developing carbon-neutral
processes in various ﬁelds such as energy, environmental andresource management.'

BARIS CAGLARSUSTAINABLE DESIGN AND
MANUFACTURING OF MATERIALSDOMINIC VON TERZIFLUID DYNAMICS FOR TRANSITION TO LOWCARBON ENERGY SYSTEMSʻI will conduct research on wind turbines andrelated ﬂow physics.ʼ
ʻThe outcome of my research will contributeto the transition to clean energy fora carbon-neutral world.ʼ

44

ʻI will conduct research on energy harvesting. The advancesof electronic engineering has made our lives easier and ourwork more eﬃcient in the past decades. However, batteries
are holding up tech breakthroughs while battery technologies
does not catch up with electronic advancements. A good
example is that our cellphones are getting smarter while
having shorter battery lives. To address this issue, harvestingenergy from environments becomes a promising solution by
harvesting ambient renewable energy, such as sunlight, heat,kinetic vibrations, electromagnetic waves and bio wastes, andconverting it to electricity. In my research, I aim to explore
novel energy harvesting techniques and power management
systems to power electronics continuously and ubiquitously.ʼ

ʻI will conduct research on fundamental
problems associated with manufacturingof thermoplastic composites, through novel
experimental and numerical techniques.

ʻThe outcome of my research will contributeto the development of eﬃcient processes
for next generation smart-composites
with reduced CO2 footprint and improved
circularity.ʼ

ʻI will conduct my research on the embedding of sensing andactuation into mechanical metamaterials. My research will
focus on using electronic and ionic smart material transducers,
and novel designs of conventional transducers. Metamaterials
are materials that exhibit exotic properties uncommon innature, and smart material transducers are material levelsensors and actuators, such as piezo electrics. By making themechanical metamaterials active, we will be able to creatematerials that exhibit tailored mechanical properties and allow
ubiquitous sensing and control over the entire material volumes
or surfaces.ʼ
ʻThe outcome of my research will contribute to innovating
human-machine interactions with increasingly interactioncapable materials for sensing and reacting to touch, and tohigh-tech engineering with highly controllable materials for
actuation, suppressing vibrations and correcting deformations.ʼ

45

fundament

AIRPLANES CROSS BORDERS, SO DO THEIR ENVIRONMENTAL EFFECTS

aerospace

FLOW DYNAMICS FOR LOW-CARBON SYSTEMS

Airplanes
crossborders
So do theirenvironmentale ﬀe cts

When it comes to the health effects of aviation,
reducing total fuel burn may not necessarily be
the optimal strategy. And, perhaps even more
surprisingly, your ﬂight from Amsterdam to Romecontributes to premature deaths in Asia. Irene
Dedoussi models the global human health impactof air pollution from aviation emissions, helping
both airplane designers and policy makers inweighing the various mitigation strategies tomake aviation sustainable.

46

47

fundament

aerospace

AIRPLANES CROSS BORDERS, SO DO THEIR ENVIRONMENTAL EFFECTSFLOW DYNAMICS FOR LOW-CARBON SYSTEMSAt university, the elegance of ﬂuid

may more than double the amount ofIn her simulations, Dedoussi takes

be as simple as an excel spreadsheet.’mechanics prompted Irene Dedoussi

nitrogen oxides released.’ The chemical

into account all the effects mentioned

Dedoussi and her colleagues do try to

to major in aeronautics rather than civil

reactions within the atmosphere are also

above as well as (global) atmosphericspeed up their current simulations, but

engineering. Then came an internship on

non-linear. They depend on the chemical

circulations patterns. It has resulted

what is unique about their approach isaircraft noise at the German Aerospacecomposition of the atmosphere which

in insights that are sometimes quitethat they design their experiments to look

Centre, where she expected to be looking

is inﬂuenced by emissions from othersurprising. ‘The health impact of nitrogenat how perturbations in the emissions

into engine acoustics. ‘But during landing,

sectors, such as heavy industry and roadoxides depends on where they areaffect global health. Then, it is easy

it is the landing gear that creates thetransport. And there is a complicatedreleased into the atmosphere,’ Dedoussi

to scale the health effects based onmost noise,’ she says. ‘I found that

relationship between air pollution andsays. ‘Airplanes are optimised for ﬂying

how much each policy or technology

strange and interesting. It made me

its health effects. Doubling or halving

fast and at high altitude largely because– a different engine, a ﬂying-V design

curious about the other environmental

emissions does not mean that the healthof economic reasons. This would,– perturbs the emissions. ‘It would

they can play a role in current technology

responds to emissions, and how

aspects of aviation and how best toeffects are doubled or halved. 'All of

perhaps, be different if the environmental

probably be naïve to think that the healthand policy decision-making.’ In thataviation contributes to the atmosphericaddress these.’ Now, as a tenure trackthese relationships need to be carefully

costs are fully taken into account.’

impact of ﬂying will be completely taken

respect, COVID-19 travel restrictions

composition,’ she says. ‘But otherassistant professor, she is establishingmodelled,’ Dedoussi adds, ‘and they comeBurning a ton of fuel over Europe has over

into account in airplane design and theand lockdowns have provided a uniquesectors, such as road transportation,

her own group on emissions and air

with a lot of uncertainties that have to beﬁfty percent higher global health impact

price of tickets,’ Dedoussi says. ‘But atopportunity. ‘The data being gathered

have also been greatly affected. Again,

quality within the Aircraft Noise andaddressed.’ʻWe, as scientists, have togive policymakers the toolsthat help them in practice.

compared to burning the same amountleast now they could play a role in theright now will be very valuable inwe have to take the complete picture into

Climate Effects section. ‘TU Delft is theof fuel over North America or Asia. ‘From

cost-beneﬁt analyses.’ For her researchunderstanding how our atmosphereaccount.’

ideal location for me to do this researcha global perspective, caring about all

into combustion emissions, she wasas it is one of the few universities

people equally, we should ﬁrst address

recently recognised as a Forbes 30 underin the world that looks into all theaviation over Europe,’ Dedoussi says.

30 in Europe’s Science and Healthcare‘But because of the circulation patterns

category.

environmental aspects of aviation,’ shesays. ‘To achieve sustainability, we can’t
look at noise, air pollution or climate
effects in isolation. There are real
trade-offs between these environmental

ʻTo achievesustainability,

in earth’s atmosphere, you will see mosthealth improvements in Asia. If you want
to ﬁx air pollution in Europe, you have to

A look into the future
When moving to the Netherlands,

we canʼt lookalso look at aviation outside of Europe.’

at noise, air

Healthy policymaking

on the deposition of nitrogen, even

Before joining TU Delft, Dedoussi

providing expert advice to a national

obtained her PhD on the atmosphericadvisory committee. ‘This is currently

impacts of ground-level and high-not being fully assessed for aviation,’ she

altitude combustion emissions at thesays. ‘Especially the contribution of high-Massachusetts Institute of Technology.

altitude emissions, if any, is completely

That was when she also became

unknown.’ She is also acutely awareinterested in the overlap with policy. ‘Ithat the health and nitrogen deposition

quickly learned that policymakers haveeffects of aviation may change over time.

a hard enough job to do as is’, she says.

That is why she recently applied for, andof these are harmful to human health, for‘They really shouldn’t also have to worry

received, a VENI grant. ‘In the future,

example causing respiratory diseases,

about the atmospheric non-linearities,

we may have higher global average

effects.’

From fuel-burn to health eﬀects –anything but straightforward
Burning airplane fuel doesn’t only create
CO2 – a major contributor to global
warming – but, among others, also
nitrogen oxides (NOx). By chemicallyinteracting with the atmosphere, thesenitrogen oxides lead to the creation ofﬁne particulate matter and ozone. Bothpollution or
climate eﬀects
in isolation.ʼ

Dedoussi quickly became involved in thesomewhat- uniquely Dutch discussions

ultimately leading to premature deaths.

Local emissions, global implications

about the details in the underlying

temperatures,’ she says. ‘Or the ammonia‘There isn’t a one-to-one relationship

By its nature, aviation is a sector thatphysics. We, as scientists, have to give

content of the atmosphere may change,

between fuel burn and health effects,’

is international. Therefore, global

them the tools that help them in practice.

which inﬂuences how nitrogen oxides

Dedoussi says. ‘For one, increasing thesimulations are needed to assess theIt can’t be an algorithm that takes weeks

react to form ﬁne particulate matter. I

airspeed and burning fuel twice as fast

health impact of cruise level emissions.

to run on a supercomputer. It has towant to model these sensitivities so that48

IRENE DEDOUSSIAssistant Professor Emissions and Air Quality49

fundament

civil

GOOD VIBRATIONS? NOT FOR BRIDGESDYNAMICS AND MONITORING OF STRUCTURES AND INFRASTRUCTURAL COMPONENTS

Good
vibrations?

ALICE CICIRELLOAssociate Professor in
Dynamics and Monitoring ofEngineering Structures andHead of the Mechanics andPhysics of Structures section

Not for bridges
Due to poor monitoring, many structures are not maintained properly
or on time. This results in safety risks and high costs for overdue
maintenance. Researcher Alice Cicirello is working on better design
and monitoring tools to ensure the secure construction of structures
to extend their service life.

Premature failures of bridges, pipelines, offshore windrisks or damage can be tackled in time.’

damage. That means the data they provide may beturbines or offshore support structures in operation

In the Netherlands too bridge maintenance has

incomplete or incorrect. This might cause missed

can have severe consequences, such as loss of lives

been found lacking. Recent research showed that

detections of unsafe structural conditions. Moreover,and unforeseen disrupting downtimes which can

the Merwedebrug, closed to traﬃc in 2016, is on thea faulty monitoring system can undermine the reasons

have safety and economic repercussions. In August

point of collapsing. In 2018 the Dutch government

for implementing monitoring technologies in the2018 Italy was shaken by the sudden collapse of the

spent around €400m on the deferred maintenance ofﬁrst place. For instance, if a structural problem isMorandi Bridge in Genova. 43 people lost their lives

bridges.

wrongly detected with a faulty sensor, the monitoringin what was later found to be an avoidable disaster50

system will give a false alarm. This would effectively

caused by years of deferred maintenance. ‘This

Failing monitoring systems

lead to an unnecessary close down of a healthy

tragedy shows the importance of constant monitoring

Monitoring of engineering structures is carried out

bridge causing huge detours for traﬃc. What I wantof structures such as bridges,’ associate professor

by means of sensors which collect data which in turnto achieve with my research are better monitoringand head of the Mechanics and Physics of Structure

are used to learn about the condition of the structure,’

strategies and design tools which will improvesection Alice Cicirello says. ‘Proper monitoring will

Cicirello says. ‘The problem is that these sensors are

structural performance and longevity. That is a major

reveal the condition of the bridge so any potential

often in the wrong place, or faulty because of age orgoal, considering the enormous maintenance and51

fundament

civil

GOOD VIBRATIONS? NOT FOR BRIDGESDYNAMICS AND MONITORING OF STRUCTURES AND INFRASTRUCTURAL COMPONENTS

replacement challenge the Netherlands is facing.

Integrated research approach

Many bridges in this country are nearing the end of

In 2017 Cicirello set up the Dynamics, Vibration

their life cycle.’and Uncertainty Research Group at Oxford andstarted a laboratory to look simultaneously at theseVibrations and other wobbles

various aspects from different angles. She brought

Before Cicirello came to Delft in January 2020

this expertise to Delft, where she is setting up theshe earned a bachelor’s and a master’s degree in

Monitoring, Vibration and Uncertainty Lab. ‘We look

Civil Engineering in Italy and a PhD in Mechanicalat physics, build mathematical models, experiments,

Engineering at the University of Cambridge. She also

quantify uncertainties and use machine learning

worked in industry and lectured at the University

techniques. An integrated approach is importantof Oxford. Cicirello’s research is centred aroundbecause it gives us a comprehensive picture of thevibration. ‘Everything around us vibrates. Vibration

behaviour of the whole of the structure. Without

enables us to hear sound and communicate withexperimenting, for instance, you won’t know if theeach other. But vibration is also a cause of structural

assumptions in the model are correct. And we needdefects or noise disturbances, not just in bridges butmonitoring and machine learning to collect andin cars, wind turbines, drilling tools and all sorts ofprocess data that will help us learn the behaviour ofother engineering devices and objects. So in order tothe structures during operating conditions,’ Cicirello

make the engineering structures last longer you havesays.

‘I look at physics, build mathematical models,
experiments, quantify uncertainties and use
machine learning techniques. Such an integrated
approach is important because it gives me acomprehensive picture of the behaviour of thewhole of the structure.’

to understand their vibration. The problem is thatthe dynamic response of a large scale engineering

A digital copy of reality

structure made of many components can be very

An integrated approach, Cicirello explains, will help

A better understanding of the vulnerable spots also

diﬃcult to predict. ‘There will always be a number

engineering structures last longer. ‘It starts withensures that maintenance is carried out at an earlyof uncertainties that inﬂuence their behaviour

the collection of information about the structure,stage and in the right places. It is also money saved

and lifespan. For bridges, these include weather

its shape, material and environment. Based on thisas preventive maintenance is much cheaper thanconditions, such as wind speed and temperature,

information, a representative computer model of adeferred maintenance. The digital twin approach also

and the impact of traﬃc.’

structure is build. This acts as a virtual replica of theextends the life cycle of the structure which saves on

structure, the so-called digital twin, which enable us

materials and energy and so beneﬁts the environment.

Uncertainties

to explore the performance of the structure before

Better monitoring also prevents avoidable delays

For Cicirello such uncertainties represent not an

it is built and also during its life cycle. For example,

caused by false alarms.’

obstacle but a challenge. ‘In science as in life, we havea digital twin of a bridge can be developed. We canto face the fact that there are many things that we dothen take into account for uncertain elements, such

Partners

improve the performance and longevity

not know precisely, and other things that are subject toas strong winds or heavy traﬃc. That will ﬂag up the

For her research Cicirello has partnered up with aof structures and infrastructures for

an inherent variability. Nonetheless we have to makecritical and vulnerable spots in the bridge. This notnumber of parties in the ﬁeld, such as the ministry ofdecisions under these uncertainties. The question is

only helps promote robust design but also determineswater management and infrastructure Rijkswaterstaat.

not so much how we can control these uncertainties

where the monitoring sensors should be placed. Once

‘Rijkswaterstaat is responsible for the monitoring

but how we handle them. One of the ways to tackle

the bridge is in use you can use the data provided byand management of many critical structures in thecommunication which are of criticalthem is for example to minimise their effect. Robust

the sensors to update the digital twin, enabling ever

Netherlands. Together we look at how their current

importance for our society.’

design can make structures as resilient as possible

more accurate life cycle predictions.’

monitoring system can be improved. Where are theagainst the effects of wind speed or heavy traﬃc‘What I want to achieve with myresearch are better monitoring
strategies and design tools which willtransportation, supply of energy and52

best spots to put the sensors, how do we prevent

which are not fully known at the design stage. A good

Advantages

the failure of the monitoring system and how do wemonitoring strategy will then help to accumulate life

Robust design and better bridge monitoring comedetermine when maintenance and repair work should

cycle data about unforeseen events and externalwith a number of advantages, Cicirello says. ‘The main

be carried out? We hope that within ﬁve to ten years

factors so action can be taken.’thing of course is to keep people safe. We have only to

we will have a number of effective tools in place tothink of the lives lost in the Morandi Bridge collapse.

make effective monitoring happen in practice.’53

fundamentelectrical

CITY OF THE FUTURE COMMUNICATES USING SOLAR PANELSCity of the futurecommunicatesusing solar panels

ELECTRICAL SUSTAINABLE ENERGY

zigzagging but clearly going up. This was theSenses and communication

surface temperature on earth. ʻThe professor

Manganiello compares the current solar

factually described the correlation between theinfrastructure with a creature that cannot see

two graphs, explaining why it is so important foror feel. It is his ambition to provide solar cells

us to ﬁnd alternative ways to produce energy,ʼ says

and modules (groups of electrically connected

Manganiello. It was this eye-opener that drove

solar cells) with these senses and enable them tohim to devote his time to the search for smart

communicate with each other and with the world.

alternatives for sustainable energy production.

The crux of the technology involves deploying
the existing infrastructure of a solar cell not only

Nearly twenty years later, Manganiello is

to convert light (photons) into charged particles

now plunging into the new research ﬁeld

(electrons), but also to provide them with sensors

of Photovoltatronics, where solar cells andthat can extract information from the light waves

electronics merge. In a nutshell, he wants toand enable them to broadcast their own light

design solar cells that not only convert light into

messages using LEDs or other light sources.

energy but are also able to send and receive

If it is up to Patrizio Manganiello, the city of the
future will not only run on solar energy, but wewill also use the solar infrastructure for lightningfast communication. Buildings will autonomously
regulate how power is distributed between them andself-driving cars will use light signals to coordinate
their driving manoeuvres. The new ﬁeld of researchcalled Photovoltatronics is bringing this future
closer.
54

Electrical engineer Patrizio Manganiello was
sitting in a lecture in Italy at the start of thismillennium when he was suddenly hit by the
undeniable reality of the disturbing headlines.
During a course on renewable energy sources,
his professor showed the students two graphs;
one displayed the trend in global energy
consumption, steeply rising like the ﬂank of ainformation. This would not only concern

Photovoltatronics – a brand new ﬁeld of research

information about the operation of the networkat the Electrical Sustainable Energy departmentof solar cells, but also other types of information,– focuses on the biggest obstacles to integratingsuch as an impending disaster. Manganiello seesenergy production and information exchange.

his work as a necessary search for a sustainable

What possible uses are there for materials

but above all fascinating future, a future in whichthat can both absorb and emit light, so that

solar panels exchange information to optimise

they combine the two functions? How can you

their operation and self-driving cars use solar

integrate LEDs and sensors in solar panels, forcells to communicate information about routes

example? ʻIn the Photovoltatronics researchand traﬃc safety. ʻAlmost anything you cangroup we see a future based on solar energy,ʼ

imagine is possible.ʼ

says Manganiello. ʻWe want to get as much as‘In time, all the buildings in a city
will be able communicate witheach other and warn each other inthe event of a ﬁre, storm or ﬂood,
for example.’mountain, while the other showed a red line,55

fundament

CITY OF THE FUTURE COMMUNICATES USING SOLAR PANELS

possible out of these solar modules both in terms of energy

information through multifunctional solar panels, theand information exchange, which will be particularly

buildings will be able to communicate with each other.

important for ensuring a sustainable energy supply in

For example, one building could report that too many

our cities.ʼ

washing machines are being used in it and that it requires

electrical

ELECTRICAL SUSTAINABLE ENERGY

extra power from its neighbour. Or they could share an
Front of clouds

internet connection using light signals. This could be of

Conducting measurements and passing on thisreal beneﬁt with the increasing scarcity of radio waves

information can primarily increase the eﬃciency ofused for Wi-Fi. In time, all the buildings in a city will besolar panels. For example, a solar panel that is equippedable communicate with each other and warn each otherto measure light intensity and temperature distribution

in the event of a ﬁre, storm or ﬂood, for example. ʻLED

can also detect a passing front of clouds. The panel canlights in an oﬃce building could send a signal to a sensor

then switch from series to parallel, so that the reduction

on your phone warning you to leave the building,ʼ saysin power of the solar cells in the shade does not hinder

Manganiello.

the energy production of those still in sunlight. When thesensors register that the front of clouds is moving away,

Self-driving cars

the panel can send a signal to a central switching point:

Manganiello explains that he has thousands of ideas forʻI am about to peak; prepare the energy network.ʼ This

experiments to bring these futuristic scenarios closer.

will prevent network overloading and instability.

ʻUnfortunately, at any given moment we can only workon a tiny percentage of these, which is what I ﬁnd most

But Manganiello also has plenty of ideas for more

frustrating about my work.ʼ He estimates that it will takecreative applications for integrating energy generation

about 10 to 15 years before new buildings will be able toand information transfer, in particular as part of thecommunicate with each other through solar cells built inincreasingly wide-scale integration of solar cells in urban

to their walls, however the ﬁrst applications should startenvironments in the coming years, where solar cells

to appear in the coming decade.

PATRIZIO MANGANIELLO
Assistant Professorof Photovoltatronics

could be built into windows and walls, but also indoors
to capture and reuse energy from artiﬁcial light. For
example, a desktop covered with solar cells could convert
the light produced by a desk lamp into energy to wirelessly
charge a phone.
The electrical engineer holds his outstretched handsin front of his chest to illustrate two buildings opposite
each other in his vision of the city of the future. If theirwalls can not only generate energy, but also exchange

Manganiello is impatient to get moving. ʻEnergy

He describes two cars, covered with solar cells

is playing an increasingly important role in ourwhich provide a large part of their energy. A deer

lives. Our biggest fear today is that our battery will

suddenly jumps out in front of the foremost car.

run out,ʼ he says. The graphs that made such an

Even before it has applied the brakes, its rear

impression on him as a student twenty years ago

lights rapidly transmit a signal to the solar cells on

have shot up even further. ʻI want to believe thatthe vehicle behind: ʻWarning, Iʼm about to brake!ʼ

we can solve this, but when I see how societies,

At the same time, the urban traﬃc control centre

governments and the industry are responding

sends signals via street lamps to solar cells on theto these issues, I sometimes lose heart.ʼ He sighs

roofs of passing cars to control traﬃc and prevent

deeply when asked to provide an example of suchcongestion and air pollution hotspots.

a response. ʻThe main problem is the resoundinglack of a response, and the low priority given toʻI think this is the best example, because safety

sustainability.ʼ

is the main bottleneck in the development ofself-driving cars, while this technology can make56

Patrizio wants to design solar cells that

Despite the severity of the problem, optimism

life easier and more sustainable. I think theand fascination still prevail in the interview

Photovoltatronics research group can provide

not only convert light into energy but arewith Manganiello. He concludes by sharing his

an important boost to the development of self-

also able to send and receive information.

favourite scenario for a sustainable future thatdriving cars, and it is a privilege to be able to

the Photovoltatronics group hopes to achieve.

contribute to this.ʼ
57

fundamentmechanical

NATURE INSPIRES NEW MATERIALS

natureinspires new
materials

ADVANCED MATERIALS FOR EXTREME CONDITIONS

If someone has bone cancer and the surgeon removes a piece ofbone, he or she replaces it with an implant. But thatʼs not as easy
as it sounds. It has to be attached to a bone, which is hard, and to
tissue, which is very soft. These kinds of transitions are diﬃcult formaterials to handle, because they have to be ﬁrm, but at the sametime they must not damage the soft tissue.

ʻWeʼre looking for ways to make materials that work well in thesekinds of transition zones,ʼ says researcher Mohammad J. Mirzaali
from TU Delftʼs 3mE Faculty. So you can make a better implant,
for example. But it can also be used in aircraft construction. An
example familiar to us all shows just how important these kinds ofhard and soft connections are. ʻThe plug of your phone charger has
a hard part that you insert into the phone, but also a cable, which
is softer. The transition from the hard plug to the cable breaks
with most people. That shows how diﬃcult it is to design this well.
Because obviously you donʼt want a charging cable that keeps
breaking.ʼ
Nature as inspiration

How do you make such a material? Mirzaali gets his inspiration'Creating new materials by learningfrom nature. ʻI let it inspire me. Nature has wonderful, ingenious
solutions for all kinds of problems. When Leonardo Da Vincifrom nature. Thatʼs what Mohammad

wanted to build a ﬂying machine, he also looked at birds and ﬂies.

J. Mirzaali is working on. He looks

I use a similar approach. I look for examples from nature that can

speciﬁcally at hard and soft transitions,inspire me.ʼwhich connect a hard bone to a piece ofsoft tissue in our bodies, for example.'

58

59

fundament

NATURE INSPIRES NEW MATERIALS

mechanical

ADVANCED MATERIALS FOR EXTREME CONDITIONS

He ﬁnds them in our bodies, for example. ʻI examine themechanism behind the transition from bone to tissue in ourbodies and I try to imitate that,ʼ Mirzaali says. He then looks at the

Nature has wonderful, ingenious

stiﬀness, which is much higher in the bone than in the soft part.

solutions for all kinds of problems.

ʻThere is a very small transition. What we see when we look inside

When Leonardo Da Vinci wantedwith special microscopes is so complicated. I want to understandexactly whatʼs at play in this transition and how it works. Thereʼs

to build a ﬂying machine, he alsodeﬁnitely a hierarchy of diﬀerent particles involved. If I can learn

looked at birds and ﬂies. I use

to understand how that works, then I can recreate it.ʼa similar approach. I look for

That's why the scientist investigates tiny particles. ʻI really lookat the forces and the structures at the cellular level. By the way, it

examples from nature that caninspire me.ʼ

MOHAMMAD J. MIRZAALI

would be a problem to create this on an industrial scale, because

Assistant Professor Biomimetics,
Biomaterials & Bioengineering

we canʼt make everything as small as nature does.ʼ
Forces at the nano-scale

For his research, Mirzaali collaborates with many colleagues fromother backgrounds. For example, he uses insights from scientists
who examine the tiniest components of our world, at the nanoscale. ʻThis is whatʼs referred to as the microfabrication of small
particles. Using artiﬁcial intelligence, weʼre trying to ﬁnd out how
certain transitions from hard to soft have been designed by nature,

What really appeals to Mirzaali is that his research is contributing

why they work and what diﬀerent types there are. These kinds of

to society. ʻIf we succeed in creating a new material, many people

collaborations always yield new insights. For example, that thewill beneﬁt from it. It can be used for many diﬀerent medical

interrelationships of the particles play an important role, that some

applications, because we have many of these kinds of transitions

designs cause certain cells to grow much faster and how individualin our bodies. Think of people with osteoarthritis. They havecells aﬀect the formation of a material. By looking at which forces

problems with their bones and tissue. Itʼs estimated that aroundare at play on the nanoscale, we can make better models for

30 to 50 per cent of people over 60 suﬀer from it.ʼdeveloping new materials.ʼ
Helping others is an important motivation, says the scientist. Thatʼs
the reason he wanted to become a doctor as a child. ʻIn the end,
I went in a more technical direction. But I still want to help others
by looking at nature to ﬁnd technical solutions. I hope that we canmanage to take our research one step further in the years to come.
By looking at multiple organs simultaneously, such as the heart andthe kidneys. At the moment, the focus is often on one body part.

ʻIf we succeed in creating a new material, many people will beneﬁt fromit. It can still be used for many diﬀerent medical applications, because

But everything in our bodies is connected. We have to look closely
at that in our work too. So, when we do something with an organ or
replace a knee with an implant, we need to look further and takewe have many of these kinds of transitions in our bodies. Think of people

into account how everything is connected. This is complicated, butwith osteoarthritis. They have problems with their bones and tissue. Itʼsalso very interesting. Weʼve still got plenty to learn.ʼ

estimated that around 30 to 50 per cent of people over 60 suﬀer from it.ʼ60

61

fundament

FUTURE RESEARCH

futureresearch

The spotlight in this Fundament magazine
is on 15 researchers who have beenworking on their research at TU Delft forsome time. But positions are still being
ﬁlled and so new researchers are starting
each month. Who are our newest talents
and what will they be focussing on?

JOSÉ ANTONIO ALVAREZ ANTOLINEZFLUID STRUCTURE INTERACTIONS FOR INFRASTRUCTURE
AND FOR NATURE BASED SOLUTIONSʻI will conduct research on nature-based solutions for coastal
resilience using emerging technologies: a highly innovative
concept that is based on tailored-Artiﬁcial Intelligence,physical systems knowledge, monitoring, and modelling.ʼ
ʻThe outcome of my research will contribute to enable
adaptation of coastal communities to climate change throughsustainable development, engineering and managementof coastal zones, by global upscaling of nature-based
solutions.ʼ

BRAM VAN DEN EIJNDENSOIL MECHANICSʻI will conduct research on geotechnicaluncertainty quantiﬁcation, ranging from thecharacterization of uncertainty in lab and site
investigation data to geotechnical reliability
analysis.ʼ
ʻThe outcome of my research will contributeto novel stochastic techniques in geotechnicalmodelling and to the uptake of reliabilitybased methods in geotechnicalengineering practice.ʼ

TON STEFAN VAN DEN
BREMERFLUID DYNAMICS AND SEDIMENTTRANSPORT IN HUMANINFLUENCED MARINE, INLAND
AND URBAN WATER SYSTEMSʻI will conduct research on transport
processes in coastal seas, focussing
on the role of surface and internal
waves and with application to, forexample, marine pollution.ʼ

LAURA STANCANELLI

ʻThe outcome of my research willcontribute to improved modellingof transport of marine pollution
including plastic and salvage of,for example, shipping containers,
and search-and-rescue missions
at sea.ʼ

FLUID DYNAMICS AND SEDIMENTTRANSPORT IN HUMAN-INFLUENCED
MARINE, INLAND AND URBAN WATERSYSTEMSI will conduct research on riverengineering, tackling interdisciplinary
issues related to aquatic ecosystems thatspan traditional subject boundaries ofenvironmental engineering and ecology.
The outcome of my research will contributeto our understanding of ﬂow-organism
interactions and behavioural responses
to natural and anthropogenic impacts.

ORIOL COLOMÉS GENEFLUID STRUCTURE INTERACTIONS FOR INFRASTRUCTURE
AND FOR NATURE BASED SOLUTIONSʻI will conduct research on novel numerical methods forproblems involving ﬂuids interacting with structures, withespecial emphasis on ﬂows with moving interfaces such as
ocean waves interacting with energy harvesting devices.ʼ
ʻThe outcome of my research will contribute to thedevelopment of digital twins of ocean energy technologies byenabling real-time simulationsof multi-phase ﬂuid-structure interaction phenomena.ʼ

62

IURI B.C M. ROCHACOMPUTATIONAL MECHANICS OF MATERIALSʻI will conduct research on novel high-ﬁdelity computational
mechanics techniques for predicting the behavior of highperformance materials and on making these techniques as
eﬃcient as possible with the aid of Artiﬁcial Intelligence(AI).ʼ
ʻThe outcome of my research will contribute to unravelling
how material behavior at very small scales inﬂuences the
behavior of very large structures, allowing a shift to asustainable structural design paradigm based on virtualmaterial testing.ʼ

63

fundament

FLINGING TINY AUTONOMOUS SATELLITES AT EARTH

aerospace

SUSTAINABLE DESIGN AND MANUFACTURING OF MATERIALS

It doesn’t sound very elegant, launching a bunch of satellites into space only tohave them plummet back to earth. But, while falling, they will map the densityof earth’s atmosphere – our shield against meteoroids and space debris. It
also involves a level of autonomy and coordination that are essential for next
generation earth observation technology and future deep space missions.

Flinging tiny
autonomous
satellites at earth
When the MIR space station decayedup, satellites have been operating for

into earthʼs atmosphere over the Paciﬁca very long time, providing valuable

Ocean in 2001, its debris was calculated

data on atmospheric density. But

to cover an area 1,500 kilometres longvery little is known about the region

and about a hundred kilometres wide.

between an altitude of one hundredʻShould this controlled descent, due

and three hundred kilometers.

to some technical malfunction, haveThanks to continuous developments

happened over Europe, you would havein nanosatellite technology, it is now

had to evacuate an entire country,ʼ says

possible, and aﬀordable, to measure

Stefano Speretta, assistant professor inthis density in great detail.

‘We can build and launch a new instrument every one or
two years, using the most recent technology and seeing
the improvement from one generation to the next.’

the Space Systems Engineering group64

at TU Delft. ʻThis large uncertainty

Chasing satellites

in where objects falling from space

In the early days of nanosatellites,

will come down is a consequence ofpeople were satisﬁed when they could

small variations in the density of thedemonstrate that they work and can do

atmosphere. These happen naturally

something useful. But now that morebecause of air currents.ʼ Using balloons

than a thousand of such satellites haveand sounding rockets, scientists havebeen launched into space, they havebeen able to build accurate models

more than proven themselves to be upof the lower atmosphere. Very highfor real scientiﬁc conquests. With his65fundament

aerospace

FLINGING TINY AUTONOMOUS SATELLITES AT EARTH

ʻcan doʼ engineering attitude and having

But Speretta, an avid lover of Star

been involved in roughly twenty-ﬁve

Trek, always has deep space in mind.

of these missions, Speretta knows how

ʻOn another planet, such as Mars, you

to push the limits of this technology to

do not have the beneﬁt of absolute

help resolve major scientiﬁc problems.

position measurements. Using two

ʻWe are developing a concept based onsatellites, or multiple pairs, all thatsatellites chasing each other throughmatters is their relative position, theearthʼs atmosphere,ʼ he says. ʻWhiledistance between them. This can bedecaying over three to six monthsʼ time,measured using a radio link or by using

their airspeed is continually aﬀecteda laser and mirrors.ʼ To ensure properby atmospheric drag. This, in turn, iscommunication and coordination

directly related to atmospheric density.ʼ

between the satellites, they should retain

A pair of big, expensive spacecrafta reasonable distance with respect towould need propulsion to prolong theireach other of somewhere between ten

descend and, thereby, the time thatand ﬁfty kilometres. The satellite that isscientiﬁc data can be acquired. Having

moving too fast may for example change

the size of a soda can and by relying

its attitude with respect to the direction

SUSTAINABLE DESIGN AND MANUFACTURING OF MATERIALS‘Distributed systems
are the next big
thing for both deep
space and orbital
applications.’of motion,
increasing its
drag and thereby‘Small variations in the density of ouratmosphere lead to large uncertainties in where
objects falling from space will come down.’

slowing it down.
Once it comessatellites mayneed to swap
is like building
a rubber bandon commercially available electronics,

between them,ʼ Speretta says. ʻWe

Sperettaʼs proposed nanosatellites arewant the satellites to be completely

both cheap to build and to launch.

autonomous in coordinating theirʻSending multiple pairs sequentiallyrelative position. Even here on earth

allows us to monitor the atmosphere forwe may not have suﬃcient time for aa much longer period of time, at a muchmanual intervention, let alone whenlower cost.ʼ

they are deployed in the atmosphere ofanother planet.ʼ

Like a rubber band

actually suﬃce as its absolute positionand speed can be determined using
the global positioning system (GPS).

Assistant Professor
Distributed Miniaturized
Instruments for Space

too close, thethis strategy. ʻIt

Here on earth, a single satellite would

STEFANO SPERETTA

Big science with many small satellites

The mission is a good example of what
is called a distributed system. It is thenext big thing for both deep space andorbital applications and a specialisation

ʻstereo visionʼ that is important for a lotof Speretta. Large systems, like theof applications – from geolocation to

Hubble space telescope, have certainly

radio astronomy. But by dividing the riskearned their place in space as they haveand tasks, each satellite can be much

unique capabilities such as a very highsimpler, smaller and cheaper, drasticallyresolution. But as they are not allowed toshortening the development cycle. ʻWe

fail, they need a lot of redundancy which

can build and launch a new instrument

increases their complexity, cost andevery one or two years,ʼ Speretta says,

development time. ʻYou may eventuallyʻusing the most recent technology andlaunch a large satellite using technology

seeing the improvement from one

that is twenty years old,ʼ Speretta says.

generation to the next.ʼ He likes to bringstudents aboard in these developments

The alternative is to distribute theto teach them much needed practical

instruments and tasks over multiple

experience. ʻAs the master track is twomuch smaller satellites, even counting

years, they can basically follow an entire

on some of these to fail. Thesedesign cycle from beginning to end. Best

distributed systems need to be able toof all, they get to reach into space.ʼ

keep their formation, as it yields the66

67fundamentelectrical

LIVING ON THE EDGEQUANTUM & COMPUTER ENGINEERING

Livingon the edge
Rajendra Bishnoi was already working in semiconductor
industry, designing hardware for computer chip memories,‘A memory that would

when he started wondering ʻWhatʼs next? Whatʼs morenormally take six

interesting, more challenging?ʼ These questions eventuallytransistors, now only

led him to Delft, where he now works on novel technologicalconcepts for so-called edge devices, and inspires students totakes a single transistor

follow his example. ʻConventional computing platforms willplus a memristor.’

start using too much energy soon. We need to look for moreenergy-eﬃcient alternatives.ʼ

Victorious artificial intelligence

From centralised to edge computing

We’re getting smarter and smarter, Bishnoi explains

This is the main motivation of Bishnoi: ‘If we continue

via Zoom. He isn’t talking about us humans, but about

on the current path, AI will consume too muchcomputer systems and algorithms. In 2015, in aresources.’ In a world where we want smart devices

visual recognition challenge, artiﬁcial intelligence (AI)everywhere, the energy demands are becoming asurpassed the intelligence level of a trained human.

serious issue. Bishnoi illustrates a possible solution

The next year, the ﬁeld hit another benchmark whenby an example of a smart security camera. ‘To do its

an AI system beat the world champion of the boardjob, this camera takes pictures and sends them to agame Go. However, these advances come at a price,central computer, where they are stored and analysed.

warns Bishnoi. First of all, the victorious AI system

Based on this analysis, the central computer could

used hundreds of central processor units (your iPhone

decide to ask the camera to move in order to betterhas only half a dozen). It also took a huge amount of

see a suspicious activity. The data transfer fromenergy, equivalent to about a million watt. Bishnoi:

camera to central computer and back again takes a lot‘I prefer to express it in terms of an electricity bill.

of time and energy. What if we make the camera just a

Getting the AI to play a single game of Go cost about

bit smarter so that it can do its own image analysis?’

300 USD.’ That bill doesn’t even include the data andThis is the ﬁeld of edge computing, where part of thetime it took to train the AI prior to playing.

required intelligence is moved from mega-scale data
centres to the edges of the network.

68

69

fundamentelectrical

LIVING ON THE EDGEQUANTUM & COMPUTER ENGINEERING‘In a world where we want smart devices everywhere,

New ways to store data

Wearable heart monitor

the energy demands are becoming a serious issue.’

These “emerging technologies” are a hot topic in

Bishnoi dreams of developing emerging technologies

computer science. Take, for example, today’s memorythat can be used for a wearable device that records

chips. They are made of millions of transistors andthe electrical signal of your heart in the form of an

capacitors, all electronic devices that have been

electrocardiogram (ECG). While smart-watch-basedaround for almost a hundred years. Bishnoi and

ECG apps are already available, they rely on thecolleagues are looking for new ways to store data

energy-consuming paradigm of sending data over theusing so-called memristors, which are tiny electronic

cloud. ‘We are dreaming of a smart-watch packed withcomponents through which small electrical currents

AI that is capable of analysing your ECG without the

ﬂow. ‘These currents depend on the resistivity of thehelp of a data centre.’ As each individual user has acomponents. As the resistivity can be programmed, adifferent heart rhythm, the AI will have a lot of learning

measurement of the current ﬂow works like reading

to do. ‘To minimise its power usage, we want it to use

out a memory. This explain the name ‘memristor’,a spiked neural network. That’s a type of AI that lies

merging the words memory and resistor. As thedormant until it detects a certain input, after which it

wire’s resistance doesn’t need any power to keep its

springs into action. Such an approach would be very

programmed state, it is an energy-eﬃcient system.

appropriate for an ECG monitor, which only needs toA memory that would normally take six transistors,

sound the alarm if the heart rhythm deviates from a

now only takes a single transistor plus a memristor.

healthy one.’

Hitting a fundamental limit

become, Bishnoi warns that it is become increasingly

While a step in the direction of energy eﬃciency, edge

diﬃcult to keep making them smaller and morecomputing is challenging us to come up with new

powerful. ‘Progress has been slowing down for theideas about computation. ‘If we want edge computing

past 15 years. As we’re nearing the scale of single

to be a success, we need to create intelligence thatmolecules, in terms of the processor speed, we areis small enough to ﬁt into the edge device, and thathitting a fundamental limit.’ A the same time, thedoesn’t require a lot of power.’ And even though ourpower required by computer chips is increasing. ‘We

smartphones are wonderful examples of how small

need to look for completely different computer chipand powerful “conventional” microelectronics havearchitectures and technologies.’

RAJENDRA BISHNOI
Assistant Professor
Quantum and Computer
Engineering (QCE)

Calculations indicate this could reduce energy usage
by a factor of 10 to 1000. Even better, memristors

Foundations for the future

allow us to read multiple – we’re currently working on

It’s impossible to predict what types of emerging

more than 128 – memory positions in one go, which istechnologies will eventually make it into production.

impossible when using traditional approaches.’But, Bishnoi is sure about one thing: ‘In 50 years’ time,
anything that can be automated, will be relying on AI.
And this AI will surely run on a very different type ofcomputing platform than we are using nowadays.’
The work by Bishnoi and his colleagues is laying thefoundations for this future.

‘In 50 years’ time, anything that canbe automated, will be relying on AI.’70

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in searchof theplastic
soup
IN SEARCH OF THE PLASTIC SOUP

mechanical

TURBULENT FLOW AND HEAT TRANSFER

Large pieces of plastic from air mattresses, bags
and packaging materials are bobbing around in
our oceans. Beneath the surface of the water, they
descend in tiny pieces almost like snowﬂakes.
They continue to sink to the dark bottom as they
pass colourful ﬁsh, enormous turtles and sea
cucumbers.
This plastic is causing massive problems. Itʼspolluting the sea and threatening marine life.

‘I’m trying tounderstand the
movement of water.
So we can predict how
plastic is spreading.’

Fish are eating it, choking on it and getting
tangled in pieces of plastic. Waves and currents
cause the plastic to travel for many kilometres at
rapid speeds. As a result, it can be found almost
everywhere. Sometimes it ﬂoats on the surface of
the water and sometimes it sinks to the seabed.
How is it possible that plastic is ending up in
so many diﬀerent places in the water? This has
to do with ﬂuid dynamics, the science of the

To better understand thewhereabouts of ﬂoating plastic
soup, you need to investigate
how the water moves at diﬀerent
depths. Angeliki Laskari,researcher of Multiphase Systems
at TU Delft, therefore studies
ﬂuid dynamics, the science of the
movement and ﬂow of water. Oneof her goals is to help predict how
plastic spreads in water.

72

movement and ﬂow of water. Scientist Angeliki
Laskari of TU Delftʼs 3mE faculty is investigating
this phenomenon. ʻIʼm trying to understand the
movement of water. So we can predict how plastic
is spreading.ʼ
Sunken plastic

That seems simple at ﬁrst sight. You can see aplastic bag ﬂoating on the water, for example.
But itʼs incredibly complicated. Because nothingis easy to predict on water. Weʼre not only
talking about large piece of plastic, like bags,
but also micro-plastics. Tiny pieces that disrupt
marine life. Theyʼre carried away by waves,currents beneath the surface of the water. ʻThe
temperature and the presence of bubbles also
play a major role,ʼ Laskari says.

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fundamentmechanical

IN SEARCH OF THE PLASTIC SOUPTURBULENT FLOW AND HEAT TRANSFER‘Sometimes we see a lot of particles in one place. Why is that?
That’s something we want to find out too. But we haven’t
reached that point yet. To make a solid prediction, you firstneed to understand exactly how all those movements under
the sea work and how particles react to them.’Thatʼs why you ﬁrst need to have solid, fundamental knowledge

Playing with waterof how water moves at various depths and also under diﬀerent

This fundamental knowledge can lead to evenconditions. Whatʼs the weather like? How warm is it at diﬀerent

more applications. For ﬂoating solar panels, fordepths? What role does turbulence, underwater vortices, play?

instance. ʻTheyʼre placed on ﬂexible structures soʻScience has already generated a lot of knowledge, so we havethey stay aﬂoat. Iʼm examining how they react todeveloped ideas about this. But weʼre not there yet. We still needwaves and the currents beneath them. Here, too,

to further improve our understanding. Particularly regarding

we want to predict how the solar panels will react

movements under the surface of the water. For example, whento the water in diﬀerent weather conditions.ʼ

plastic has sunk.ʼ
This combination of fundamental research,Particles in a pipe

which examines how something works, with

Laskari conducts many experiments in the lab at the 3mE faculty.

practical applications appeals most to Laskari.

She looks at ﬂows that not only contain water, but also bubbles

ʻIt gives me great satisfaction to know that myand small particles. ʻWe want to know how all of this moves underwork is socially relevant. I want to do my part anddiﬀerent conditions. If you shine light on it, you can barely see

contribute to something that makes the world athrough the particles. Thatʼs why we measure what happens with

better place. At the same time, I ﬁnd it fascinating

ultrasound. You can compare this with the technology used toto discover exactly how things work. Thatʼs why

create images of babies in the motherʼs womb. We use similar

the fundamental side also appeals to me.ʼtechnology to visualise how everything moves in the pipe.ʼ

Itʼs no coincidence that Laskari is working

Itʼs diﬃcult to interpret these images with the naked eye, however.

with water. Sheʼs from Greece, where she spent

Everything is constantly moving in the water: all kinds of particles

summers on Serifos, one of the countryʼs manyof diﬀerent sizes, as well as air bubbles. ʻThatʼs why weʼre using an

islands. ʻThere was water everywhere. My father

algorithm, a calculation program that monitors how everything has

had a small boat and we often went sailing in it.

When a piece of packaging

moved. This allows us to see the speed, height and concentration of

I played near the sea almost every day. One of thematerial blows into the sea inparticles.ʼ

reasons that I love living in the Netherlands is

The ultimate goal is to predict where the plastic will end up. Whenthat thereʼs water everywhere here too.ʼ

'The ultimate goal is to predict
where the plastic will end up.

Scheveningen, you know that

74

Assistant Professor
Multiphase Systems

a piece of packaging material blows into the sea in Scheveningen,certain parts of it will end up

you know that certain parts of it will end up in Den Helder and

So itʼs a subject that has a ﬁrm hold on her. ʻIt

in Den Helder and others nearothers near Dover or even Boston. ʻSometimes we see a lot ofstill makes me curious. Water is never boring. Itʼsparticles in one place. Why is that? Thatʼs something we want toconstantly changing. Thatʼs why itʼs so diﬃcult toﬁnd out too. But we havenʼt reached that point yet. To make a solid

predict, because you have to study everything you

prediction, you ﬁrst need to understand exactly how all thosewant to say about it very carefully ﬁrst. In fact,

movements under the sea work and how particles react to them.ʼ

thatʼs why the subject still has my attention.ʼ

Dover or even Boston.'

ANGELIKI LASKARI

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fundament

COLOFON

ColofonRedactie TU Delft
Dave Boomkens EEMCS
Fien Bosman 3mE
Marije Gordijn AE
Karlijn Spoor CEG
FotograﬁeFrank Auperlé
Guus Schooneville (pagina 2)
Pieter Lemmens (pagina 22- 25)
Tekstschrijvers
Robert Visscher
Diederik Rep
Hidde Jansen
Merel Engelsman
Marieke Buijs
Vormgeving
Hollands Lof, Haarlem
Drukker
Van der Heijm, Schiedam

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