• Commenting on the Micromachine
Drawing Contest• Tactile Sensors Res. at Shizuoka
Institute of Science and Technology• MMC’s Act. in F.Y. 2000 / 7th Res. Grant/ Oita Micromachine Seminar / 6th
Drawing Contest• Members’ Profiles••

AISIN COSMOS R&D CO., LTD. /OMRON Corporation
Foreign View
MEMS 2000
Introductory Course
Latest Micromachining Technology (I)3Commenting on theMicromachine Drawing
ContestRyoze Yamashita
Associate Professor,
Tokyo National University of Fine Arts and Music

This marks my third to participate in thescreening of the Micromachine Drawing Contest.
This contest is quite intriguing with a considerable number of entrants attending, classified into
school children from primary and junior highschools.
For those school children, the micromachine is
not a real device, but a future or imaginary one.
This contest, therefore, aims at screening imaginary pictures. This screening emphasizes not on
the excellence of a little artist expresses or tries toexpress his or her idea, suggestion or hope in the
picture, that is, how he or she thinks about the
micromachine.
It is widely known that a picture enriches ourinner selves in a broad sense, particularly when
we draw imaginary pictures. Drawing imaginary
pictures is quite effective for training our minds
to nurse flexible thinking.
What we envisage is fragmentary like a jigsaw
puzzle. By drawing a picture, however, our imagination works to fill up what is vague, enabling us
to expand our imagination.
The sense of filling up and the energy to expand activate our brains.
On finding that it is easier to understand what
we think if we draw a picture, I was beside myself
with joy as a fifth-year-grade boy. I disliked schooling except for drawing and manual arts, which I
liked best, physical education, which made me feel
happy, and science, which I liked a little bit. One
day, however, our teacher wrote an arithmetic problem on the blackboard saying “This problem is hard
to solve. Solve it, the lot of you”. On it, a picture
flashed into my mind.
I drew the picture in the notebook, and I readily
solved it.
After that, I became able to solve a problem
much faster than any other classmates if the problem allowed me to develop my imagination into a
picture. That was the only occasion when I felt
schooling to be quite fun.

2

Now, I’m teaching students while working on
my art using the technique of dyeing.
The world of art is divided into various fields(or genres), such as paintings, sculpture, craft, anddesign. However, every field is based on drawing a
picture.
It is very rare that a work is finished straightfrom an inner imagery itself.
First, I draw a picture. The picture is not for
showing to others, but for making a decision on
my own whether the image can be made into awork after seeing it with my own eyes. The picture does not have to be complete. It suffices if I
can draw to an extent where I can determine on
my own. This stage is called “Idea sketch” or “Image design”, and is most important process of making.
I draw pictures on one sheet after another until the picture comes close to the image. The imagechanges, however, while drawing on one sheet after another. The image may change since it is vague
in my mind. The image gets going after I see thepicture I drew for activating my mind to work.
My hand keeps chasing an image in the beginning until finally the image chases my hand, a condition most desirable. When I draw a picture, it
propels what is in my head rather than depicts/
illustrates what is in my head.
A student often says “I’ve not drawn a picture
yet, but an image is in my head”. However, this ismistaken. He is in a state where an image whichshould be vague and mobile has been fixed as anillusion, because of the image being unmoved. This
state does not lead to a final piece. An image could
be real when visualized by using your hands.
When screening in the “Micromachine Drawing Contest”, I have come across many pieces ofwork that induce me to think that “Brains andsenses work flexibly by drawing a picture”.
It may not be a dream that a Leonardo da Vinciin the 21st century may emerge from among them.

Probing the Micro-World throughTactile Sensors

Associate Professor Masahiro Ohka

Faculty of Science and Engineering, Shizuoka Institute of Science and Technology

1. Introduction
This laboratory, called “Intelligent Sensing Laboratory”, is conducting scientific research chiefly to tactile
sensors, tactile information processing, and tactile display systems. As a micromachine-related theme, it issetting about dealing with “Tactile Microsensors”, aneffort to minimize a tactile sensor to the utmost limits.

tant technology is under way now for the realization ofthis ultimate goal. With the subsidy granted by the Foundation Micromachine Center, a tactile sensor could be
developed for mounting on a microrobot. In addition, amaster manipulator is also being manufactured on a
trial basis for mounting on a tactile information display
unit, the details of which will be described below.

2. Tactile Microsensors / Display Systems
A microscopic type microrobot often contacts tube
walls. It is therefore considered effective to mount a tactile sensor on the robot for the protection of the robot
itself as well as for the prevention of tube wall damage.
Generally, a tactile sensor indicates a sensor by which
the distribution of contact-induced pressure can be measured. For the control of the attitude of a microrobot
moving along the wall tube, however, it appears necessary not only to measure the pressure distribution but
also to detect shearing stress that works in the direction of friction.
In addition, more dexterous operation of the
microrobot can be realized if the tactile information,
obtained by the microrobot on contact, could be effectively displayed to the operator. Since the tactile information the microrobot acquires is minute, it becomes
necessary to enlarge it for display instead of displaying
it as it is. In the master-and-slave-mode control as shownin Fig. 1, it is easy to enlarge a display as desired because of the presence of a computer between the masterand the slave.
The system shown in Fig. 1 is an ultimate goal ofthis research. Research and development of the impor-

3. Tactile Microsensors
This tactile sensor utilizes a phenomenon in which
diffused reflection is caused at a part of the contact between a light guide and a rubber sheet. When a small
conical projected array is formed at a part of the contact
between a rubber sheet and a light guide, the area ofcontact of the conical projection increases in proportion
to contact pressure. This enables the distribution of contact pressure to be obtained by measuring the distribution of luminance after the conical projection contact
part has been photographed with a CCD camera as
shown in Fig. 2. The distribution of shearing stress canalso be obtained by measuring a travel distance since
the conical projection moves horizontally in proportion
to the degree of shearing stress.

Fig. 2 Principle of Tactile Microsensor

Fig. 1 Tactile Microsensor/Tactile Information
Display System

An experimental system was structured as shownin Fig. 3 to confirm the above principle. This system iscomposed of a tactile sensor, a bore scope, an electronicbalance, a parallel-plates typed force sensor, and two
dynamic strain gauges. The electronic balance was used
for calibrating vertical force while the parallel-plates
typed force sensor and dynamic strain gauges were used
for calibrating load in the horizontal direction.

3

Fig. 3 Prototype of Tactile Microsensor System
Fig. 4 shows vertical force detection characteristics.
As the figure clearly indicates, load and luminance values exhibit high linearity. Horizontal force detection
characteristics are given in Fig. 5, which reveals thatthe relationship between horizontal force and horizontal travel distance also shows linearity.

Fig. 4 Vertical Force Detection Characteristics

Fig. 5 Horizontal Force Detection Characteristics

4

4. Tactile Information Display System
This tactile microsensor, with an ability to measure
three-axis force distribution, must also be able to display the three-axis force for a system that displays thetactile information measured by this sensor. The tactile
information display system on which this laboratory is
carrying out research is also expected to be developedin a manner that will be able to display ultimately threeaxis force distribution. Introduced here is a tactile information display system manufactured on a trial basis
to display pressure distribution.
Fig. 6 gives an experimental unit consisting of an XY table with an air bearing, an encoder, a DC motor, anda tactile information display unit. On the upper surfaceof the tactile information display unit are arrayed 2 × 2
projections that transmit pressure to the finger. The
operator can freely move this display part in the twodimensional plane with his finger pressed on the arrayof this display point. Since this movement is measured
by the encoder, a slave robot can be moved according to
the value measured. A system, similar to the one shownin the beginning in Fig. 1, can be realized by mounting
the tactile sensor, shown in the foregoing Fig. 3, on theend effector of the slave robot. Now under study are theenlargement of an array scale of the tactile information
display part and a method of displaying shearing stress.
5. Conclusion
At this stage, we are far behind our future schemeas described in the beginning, and therefore must study
further as well. As a tactile sensor becomes smaller, ahigher technology is required for machining parts withthe tactile sensor. We also feel strongly the necessity fora cleaner, vibration-less experimental environment.
In view of the foregoing, we are not only trying to
put the experimental environment in order, but also looking for a way out while studying another principle. For
example, we are also planning an experiment in which
the results detected by using the AFM (Interatomic ForceMicroscope) as a tactile sensor can be displayed on thetactile information display unit introduced herein. It isquite likely that we will be able to touch and feel a nanometer world in the near future.

Fig. 6 Prototype of Tactile Information Display Unit

Overview of MMC’s Activities
in Fiscal 2000
In F.Y. 1999 the Micromachine Center (MMC) will implement the following five programs with the aim of establishing
the basic technologies for micromachines and increasing utilization of micromachines.
① Investigations and research on micromachines,② Collection and provision of micromachine information,③ Exchange and cooperation with worldwide organizations
involved with micromachines,④ Promotion of standardization of micromachines,⑤ Dissemination and education about micromachines.
I. Investigations and Research on Micromachines
The Industrial Science and Technology Frontier Programof MITI’s Agency of Industrial Science and Technology (AIST)
has entered the final year of its second phase. To achieve thegoal of the basic plan for the R&D (Phase II), the R&D system
will be further improved and research delegated to MMC will
be actively promoted. Also MMC will exchange technical information with researchers in various countries and provide results of investigations and research for those concerned in andoutside of Japan.
1. The AIST’s Industrial Science and Technology Frontier
Program “Micromachine Technology” (This project has beendelegated to MMC by the New Energy and Industrial Technology Development Organization (NEDO).)
Based on the R&D results on fundamental device technology in the first phase, the ultimate purpose of this project is toestablish technologies applicable to the realization of
micromachine systems. These systems are mechanical systems
composed of small functional elements that locomote withinvery narrow spaces in complicated facilities for a power plantand inside of the human body. They can also perform intricate
work autonomously, and produce small industrial products asa microfactory. Following research will be conducted in F.Y.
2000.
(1) Development of advanced maintenance technologies for
power plants① R&D of systematization technology (Experimental wireless micromachine for inspection on inner surface of tubes)
R&D of systematization technology will be conducted
through production of an experimental system for a wirelessmicromachine. Inside a metal tube with a curved section, thismicromachine will be able to move forward, backward, horizontally and vertically, stop optionally, and recognize its surroundings as well as detect defects of tubes. R&D topics promoted are realization of an experimental wireless micromachinefor inspection on inner surface of tubes through developing a
locomotive device and a microwave energy-supply/communication device as the main technology, and systematization of a
microvisual device and an optical energy transmission device.
② R&D of systematization technology (Experimental chaintype micromachine for inspection on outer surface of tubes)
Systematization technology will be developed through production of an experimental micromachine system composed ofa group of single machines capable of combining or separating

according to the form of the object to be inspected. R&D will
promote the following topics: creation of an experimental chaintype micromachine for inspection on outer surface of tubes
through developing a driving device to propel the machine, andsystematization of speed reduction and traveling devices anda microconnector.
③ R&D of systematization technology (Experimental cathetertype micromachine for repair in narrow complex areas)
R&D on systematization technology will be conducted byproducing an experimental micromachine system capable ofentering the equipment of various structures and performing
measurements or repairs of minute flaws. R&D topics promoted
are: creation of an experimental catheter-type micromachinefor repair in narrow complex areas through developing multidegrees of freedom flexible pipe structure; and systematization of a position detection device and a monitoring device.
④ R&D of functional device technologies
R&D will be conducted to promote micronization, high performance, and multi-functionalization of functional devices thatform the components necessary to realize future micromachine
systems and highly advanced micromachine technology. R&D
will focus on creating the following: an artificial muscle,
microjoint, low-friction suspension device such as magnetic
bearing, micro-battery, optically driven free joint device, etc.
⑤ R&D of common basic technologies
R&D will be conducted on common basic technologies suchas technologies for control, measurement, design, and evaluation necessary for realizing micromachine systems. R&D will
center on achieving pattern forming technology for a group of
distributed micromachines, hierarchical group control technology, measuring technology for micromachines, etc.
⑥ Comprehensive investigation and researchComprehensive investigation and research on micromachine technology will be promoted including investigation andresearch to conduct the conceptual design of maintenancemicromachines necessary for maintaining future power plants,
and leading investigations and research on micromachine systems expected to be used for maintenance.
(2) Development of microfactory technology① R&D of systematization technology (Experimental processing and assembly system)
R&D will be conducted on systematization technology by
producing an experimental system for processing and assembling capable of manufacturing models of small parts by integrating processing, assembly, conveyance, and inspection machines in a limited narrow space. R&D topics promoted include:
micro processing technology, micro assembling technology, micro fluid technology, micro optical driving technology, micro electric driving technology, micro conveyance technology, and micro inspection technology.
② Comprehensive investigation and researchComprehensive investigation and research on micromachine technology will be promoted. This will include the influence of microfactories caused by such problems as electromag-

5netic interference generated when various devices are integrated or concentrated in a small space, and advanced researchon micromachine systems to be used in production. In addition, we will conduct research on enhancing the performanceof micro-electron guns for beam processing jointly with AIST’s
Electrotechnical Laboratory.
(3) Research and development of micromachine technology① Research on micromachine systems
In the medical field, R&D on miniaturization and multifunctionality of micro-laser catheters and micro-tactile sensor
catheters will be conducted. These catheters are the major functional components of a micro-catheter for diagnosis and treatment of cerebral blood vessels, an intraluminal diagnostic, andtherapeutic system. In addition, R&D on a scanning-type imaging tube unit for medical micromachines will be conducted.
② Comprehensive investigation and researchComprehensive investigation and research on micromachine technology will be carried out on the future applicationsof micromachine system to the medical field. In conjunction
with AIST’s Mechanical Engineering Laboratory, MMC will also
conduct research on micromachine basic design and manufacturing technologies.
2. Research and Development on the Application and Extension of Micromachine-based Systems to Industry (activities to help promote the machine industry)
Forecast of the future application and extension of micromachine-based systems to industry will be conducted, and the route
to practical use of micromachine technology will be revealed.
Thereby, aiming to promote the introduction of new technologies to various industrial fields, ① investigations on current
states and roadmap surveys on key-technologies in various
fields, and ② roadmap surveys on the application and extension of micromachine-based systems in various fields, and surveys on their application and extension in other fields and in
new uses, will be conducted.
3. Research and Development of the Applicability of Emerging Technology in Other Fields to Micromachine Technology (activities to help promote the machine industry)Pursue joint efforts among government, academia and industry to search out emerging technology in other necessary
fields in order to promote the diversification and practical useof micromachine technology, and to verify its applicability andfusion. In this fiscal year, we will search out emerging technology in the bioscience, chemical, physical science and medical
fields.
4. R&D of Micromachine Materials
Jointly with the Mechanical Engineering Laboratory of
AIST, MMC will conduct ① research on the operating environments for micro functional elements, ② research on micromachine materials, and ③ feasibility studies on micromachinematerials.
5. Investigation on R&D Trends of Micromachine Technology
in Japan and Abroad
MMC will analyze the current state of research and development on rapidly progressing micromachine technology inJapan and abroad, and develop a body of information on thebasic technologies for developing micromachine technologies.
II. Collection and Provision of Micromachine Information
Information and documents on micromachines in universities, industry, and public organizations in Japan and over-6seas will be collected, combined with survey results and documents produced by MMC, and made freely available in the
MMC library and through MMC’s internet web site.
III. Exchange and Cooperation with Worldwide Organizations Involved with Micromachines
To promote affiliation, exchange, and cooperation with related organizations in and outside Japan, MMC will implement
the following. ① Hold the 6th Micromachine Summit inHiroshima. ② Hold the 6th International Micromachine Symposium. ③ Provide research grants to research activities atuniversities for R&D on micromachine technology as part ofits promotion of joint research with government, industry andacademia. ④ Invite authorities from overseas, and dispatch
authorities from Japan, to promote overseas exchanges. ⑤ Dispatch research missions overseas. ⑥ Hold joint seminars andworkshops overseas.
IV. Standardization of Micromachines
1. Development of the International Standardization for supporting new industries “Standardization of the evaluation
methods of material properties for micromachines” (Thisproject has been delegated to MMC by the New Energy
and Industrial Technology Development Organization(NEDO).)
MMC will develop a standard tensile test method that canevaluate mechanical properties of various kinds of thin films
of about 10µm thick and under 100µm width, and will make it
as an international standard. Concretely, we will clarify measuring methods of the stress and strain, loading methods ofspecimens, and their sizes and shapes, aiming to make drafts
of international specifications through improving and synthesizing the various kinds of test methods which have been proposed now, and defining their applicable ranges. In this fiscal
year, we will conduct round robin tests which evaluate the same
specimens with using different test methods.
2. Investigation and Research on Micromachine Standardization
Based on progress in standardization as planned in F.Y.
1998, MMC will implement the following. ① Promote theMicromachine International Standardization Forum established in F.Y. 1998. ② Based on “Technical Terms in Micromachine Technology” issued in 1998, cause micromachine glossary to reflect the results of the Forum, while at the same time
expanding content from the standpoint of international standardization. ③ With regard to measurement evaluation methods, study collation of past research results into a comprehensive technical report, pursue research into specific standardization topics deemed necessary, and move to standardize theirtechnical issues.
V. Dissemination of and Education about Micromachines
In order to achieve wider utilization of micromachines,
MMC will implement the following. ① Issue public information publications. ② Hold the 6th Micromachine Drawing Contest, seminars on micromachines, briefing session on research
results, and preparation of videos. ③ Hold the 11th Micromachine Exhibition. ④ Serve as the Federation of MicromachineTechnology Secretariat.

The Research Subjects for the 7th
Micromachine Technology Research Grant
The research subjects for the 7th Micromachine Technology Research Grants (for F.Y. 1999) were selected at the Boardof Directors meeting held in March 2000. As a result of a rigorous screening and examination process, seven new researchsubjects and six ongoing research subjects (2nd year) were selected from a large number of applications, as shown in the
appended table.
A total of ¥20.3 million in financial assistance grants will
be presented. This research grant program was started in F.Y.
1993 as an independent activity of the Micromachine Center,and provides financial assistance to researchers engaged inbasic research on various aspects of micromachine technologies. It is aimed at providing support for further progress of
micromachine technologies, and at promoting exchange andcooperation between industry and academia.
On March 27, 2000, a ceremony to award the research
grants was held at the Tokai University Alumni Hall in the

Kasumigaseki Building. Dr. Tsuneo Ishimaru, Chairman of theMicromachine Center, gave the sponsor’s greeting. Mr. Masahiro
Fujita, Director, Industrial Machinery Division of MITI, gave
his guest speech, and Prof. Yoji Umetani, Chairman of the Industry-Academia Joint Research Committee of theMicromachine Center, reported on the results of the screening.
Following this, financial assistance awards were presented tothe thirteen researchers who were selected. Prof. TakehikoKitamori of The University of Tokyo spoke on behalf of the grantrecipients. Later, each of the seven researchers on the new research subjects that were selected gave overview of his research,followed by an informal discussion.
Applications for the F.Y. 2000 research grant program will
be solicited and accepted from July to October of this year.
The new research subjects that were selected for the 7th
Research Grant are summarized in the following pages.

Subjects for the 7th Micromachine Technology Research Grant
New Research Projects Granted for Fiscal 1999
Leader & Co-Worker
Dr. Masayuki Yamato

Affiliations
Subjects
Research Assistant Professor, Institute of Biomedi- Development of noninvasive single
cal Engineering, Tokyo Women’s Medical Univercell manipulator utilizing temperasity
ture-responsive polymer
Department of Biological Science and Technology, Construction of micro-lens array by
Prof. Yoshihiro Ito, Dr. Eng.
Faculty of Engineering, The University of
micro-fabrication of stimuli-responTokushima
sive gel
Assoc. Prof. Kazuhiko Ishihara, Department of Materials Science, Graduate School Study of novel polymer microof Engineering, The University of Tokyo
actuator powered by enzymatic
Dr. Eng.
reactions of biomolecules
Research Associate, Department of Engineering
Catheter tip position sensing system
Dr. Yoichi Haga
Research, Tohoku University Graduate School
using MI sensor
Faculty of Engineering, Kagawa University
Electrical, thermal and mechanical
Assoc. Prof. Gen Hashiguchi,
properties of nano mechanical
Dr. Eng.
Institute of Industrial Science, The University ofstructures
Prof. Hiroyuki Fujita, Dr. Eng.
Tokyo
Research Associate, Institute of Industrial Science,
Dr. Manabu Ataka
The University of Tokyo
Coordinate measuring machine
Assoc. Prof. Takaaki Oiwa, Dr. Faculty of Engineering, Shizuoka University
using parallel mechanism forEng.
micromachine parts
Prof. Takehiko Kitamori, Dr. Eng. Department of Applied Chemistry, Graduate School Integration of chemical systemsof Engineering, The University of Tokyo
toward artificial organ
Lecturer, Department of Applied Chemistry, GraduDr. Hideaki Hisamotoate School of Engineering, The University of Tokyo

Period2 Years
2 Years
2 Years
2 Years
2 Years

1 Year
2 Years

Carried-Over Projects Granted for Fiscal 1998
Leader & Co-Worker
Prof. Masao Washizu, Dr. Eng.

Affiliations

Department of Mechanical Engineering, Kyoto
University
Prof. Kazunori Kataoka, Dr.
Department of Materials Science, GraduateEng.
School of Engineering, The University of Tokyo
Dr. Atsushi Harada
Research Associate, Department of Materials
Science, Graduate School of Engineering, The
University of Tokyo
Dr. Tooru Ooya
Research Assistant Prof., School of Materials
Science, Japan Advanced Institute of Science andTechnology, Hokuriku
Dr. Hiroshi Toshiyoshi
Lecturer, 3rd Division, Institute of Industrial
Science, The University of Tokyo
Prof. Hiroyuki Fujita, Dr. Eng.
3rd Division, Institute of Industrial Science, The
University of Tokyo
Prof. Shigefumi Nishio, Dr. Eng. 2nd Division, Institute of Industrial Science, The
University of Tokyo
Dr. Kiyoshi Takano
Research Associate, 2nd Division, Institute ofIndustrial Science, The University of Tokyo
Assoc. Prof. T. H. Barnes
Physics Department, University of Auckland

Subjects

PeriodMolecular surgery of DNA based on
microsystems
Structural design of “chemical nanomachine” based on the selforganization of polymers and its
application to targeting therapy

2nd Year

Study on biomedical micromachineusing biodegradable supramolecularassembly
Micromachine system for microoptical smart pixel application

2nd Year

Experimental study on fluid flow andheat transfer inside micro-channel
utilizing micro-machining technology

2nd Year

2nd Year

2nd Year

Low-noise feedback interferometry for 2nd Yearmicromachine servo actuators

7

Construction of Micro-Lens Array by MicroFabrication of Stimuli-Responsive Gel
Yoshihiro Ito
The University of Tokushima

Mr. Fujita, Director of Industrial Machinery Division, MITI,
gives his greeting.

In this research, we will create a micro lens array withvariable focal length by micromachining a gel which expands
and contracts in response to electrical stimulation. By using
this array, we will create a device which can improve image
processing efficiency by adjusting the lens focal length only inthe region corresponding to the particular image to be sharpened among the images already captured on the light-receiving surface. Moreover, we intend to create a lens array on a
curved surface in order to apply it to a new compound-eye system. Stimulation-responsive intelligent gel micromachining as
described here is expected to become an important basic technique for micromachine engineering in the future.
Light

Light

Researchers who received research grants for F.Y. 1999

Focus
adjustment

Outline of the New Subjects
for the 7th MicromachineTechnology Research Grant
Development of Noninvasive Single Cell
Manipulator Utilizing Temperature-ResponMasayuki Yamato
sive Polymer
Tokyo Women’s Medical University

Recently, there has been an increased need for research into
the next generation of artificial organs. This had led to the necessity for better understanding of cell-cell interactions in tissues and organs which are composites of various cell types. Therefore, there is an urgent need to develop a technique for the threedimensional arrangement of the different cell types. Single cellmanipulators having the necessary technology for effective cellattachment and detachment of selected cells in a noninvasive
manner will be a very useful and important tool. Such manipulators could also be used for gene introduction, nuclear replacement and so on. Here we propose to develop a single cell manipulator which enables selective switching between cell attachment and detachment using a temperature-responsive polymer
and a Peltier device for temperature control.

Image extracting region

Extracted image

Study of Novel Polymer Microactuator Powered by Enzymatic Reactions of Bio-molKazuhiko Ishihara
eculesGraduate School of Engineering,
The University of Tokyo

In order to operate a micromachine in a living body, it isvital for the machine to generate energy in the body, rather
than obtain energy externally. Therefore, in this research, itwill be created an actuator combining an polyelectrolyte andredox polymer, the structure of which change in response to
the chemical information distinctly translated from the glucose and lactic acid present in the body by using enzymatic
reactions. In addition, it will be developed basic techniques forcreating a device which allows the actuator to actuate medicalelastomer films with improved biocompatibility and make themmove like the fins of fish.

Peltier device
Polymer microactuator
End cap section(biocompatible polymer coating)

Copper wire

Polymer microactuator
GOD-immobilized polyelectrolyte film+
LDH-immobilized redox polymer film
200 µm in thickness (100 µm× 2)

Biocompatible segmented
polyurethane (SPU) film

Glass capillary
Reversible change in volumeof polymer microactuator
Moving section
like the fins of fish

32˚C or higher: hydrophobic Facilitating cell attachment
Capillary end
PIPAAmPIPAAm-grafted
surface

Less than 32˚C: hydrophilic Facilitating cell detachment

Target cell

PIPAAmTarget cell10 〜 20 µm
Switching from hydrophobicity to hydrophilicity by setting
the capillary end temperature to less than 32˚C

Image Diagram of Cell Manipulator Use

8300 µm500 µm
Biocompatible SPU film (50 µm in thickness)

Target cell
Outline of Polymer Microactuator Using Biomolecular
Reaction as Energy Source

Expected Size of Polymer Microactuator

Control of the reaction by regulation of glucose diffusion (polyelectrolyte)
GlucoseVolumecontraction

Glucose oxidase (GOD)
Hydrogen peroxide + Gluconic acid

Dihydronicotinamide group(NADH), Reduced form
No charge,hydrophobic Redox polymer
Pyruvic acid

Volume expansion

Nicotinamide group(NA), Oxidized form
Lactatedehydrogenase
Lactic (LDH)acid

Positively
charged,hydrophilic

Operation Mechanism of Polymer Microactuator Using Biomolecular Reaction as Energy SourceCatheter Tip Position Sensing System Using MI Sensor

Coordinate Measuring Machine Using Parallel Mechanism for Micromachine Parts

Yoichi Haga
Tohoku University

Takaaki Oiwa
Shizuoka University

We will develop a system which detects the three-dimensional position and attitude (direction and torsion) of the tip ofa medical catheter by equipping the catheter with micro magnetic vector sensors, which detect the magnetic field createdby an external coil.
If this sensor system is compared to a car navigation system, the catheter tip corresponds to the car, and the blood vessels to roads. Before operation, three-dimensional blood vessel
images are obtained and storaged in a computer by using contrast medium CT or MRI, and the three-dimensional position
and attitude of the catheter tip is detected and superimposed
onto the blood vessel images on the screen. This system is also
expected to be applied to an endoscope.

While the machining of precision micro parts with threedimensional, complex shapes is being realized, their geometrical deviation measurements need to be performed on a threedimensional basis. In this research, we will investigate a small
three-dimensional coordinate measuring machine (CMM) for
high-precision three-dimensional measurement of the geometrical deviation of a 20 × 20 × 20 mm micro part. Thus we will use
a parallel mechanism, which contributes to high stiffness, precision, and speed, rather than a slide mechanism, such as theconventional rectangular coordinate type. Moreover, we propose a micro CMM that employs elastic hinges, and is free fromthe effects of friction and wear, as revolutionary pairs (joints).
Actuator+ linear scaleComputerCatheter
3-axis MI sensor

Frame
Automatic
probe changer(3D touch probe+ tools, etc.)

Patient

3D blood
vesselimage
Excitation
coil

Signalprocessor

Catheter

Spherical joint
Prismatic joint

Data of3D blood
vesselimage

Universal joint
Work
Probe
Working space: 20 × 20 × 20 mm

Conception of Parallel Mechanism
Type Nano-CMM for Micromachine Parts

Electrical, Thermal and Mechanical Properties of Nano Mechanical Structures

Integration of Chemical Systems toward
Artificial Organ

Gen Hashiguchi
Kagawa University
Hiroyuki Fujita and Manabu Ataka
The University of Tokyo

Takehiko Kitamori and Hideaki Hisamoto
Graduate School of Engineering, The University of Tokyo

There have recently been growing expectations for the development of new functional devices using mechanical structures in the order of nanometers. However, little is known about
the physical properties of nano-structures. This research is intended to reveal their properties by performing precise measurement of their physical-to-electrical-quantity conversion
properties by means of a four-terminal nano-device. The line
width and thickness of the four-terminal nano-device to be created will be 30 to 100 nm. The results of this research willraise expectations for realization of super-high performance
sensors and devices using nano-structures.

We will integrate chemical reaction, separation and detection systems for liquid-phase chemical processing system by
micromachining a micro channel network within a glass microchip. In this research, we will determine the size effects onmolecular behavior and chemical reactions in liquid-phasemicro space, and develop methods concerning highly efficientchemical reactions and their control. Among other things, wewill demonstrate that the boundaries between liquids – liquidliquid interfaces – in liquid-phase micro space are similar to
those of living cells, and so construct a chemical system similar to the living organ. Also we will realize artificial micro biochemical systems such as diagnostic devices and detox devices
incorporating immunoreactions or enzymatic reactions.

Excitation by
light, heat, or
electromagnetic
waves
SPM
machining

Detection

Drain

30nm 〜 100nm

Functional
material
deposition

Reagent C

100nm 〜 10µm

Reagent B
Specimen

Separation
Reaction
MixingReagent A
Channel width: 1 to 100 µm

9Oita Micromachine Seminar

10

Oita Micromachine Seminar was held in the afternoon of February 10, 2000 at Oita Industrial
Research Institute in Oita City. It was organizedby the Micromachine Center and Oita Industrial
Research Institute, and officially supported by the
Oita Industrial Creation Organization, Oita Industrial Technology Research Society, and Oita Machine Technology Research Society.
At the seminar, in addition to presenting recent developments in micromachine technology, an
overview of Micromachine Technology Researchand Development, an Industrial Science and Technology Frontier Program project currently being
carried out under MMC’s leadership, and four concrete results were presented.
In addition, during breaks, Mr. Takashi Kawano
and Mr. Tsuneji Yada, General Manager of the Information Department gave demonstrations of“Laser Powered Micropump” (made by AISIN COSMOS R&D CO., LTD.) and “In-Pipe Micro Inspection Machine” (made by DENSO CORPORATION),
both of which were exhibited on site. The exhibits
and presentations provided a good opportunity forthe attendants to learn about micromachine technology.
The master of ceremonies for the seminar was
Mr. Yoshiomi Goto, Manager of the Mechanical andElectronics Technology Division of Oita Industrial
Research Institute, while the chairman for theseminar was performed by Mr. Tatsuo Sato, Chief
Researcher for the Institute.
The program opened with a welcome by Mr.
Hideo Tsukune, Director-General of the Oita Industrial Research Institute, after which a seriesof presentations ensued. Mr. Hajime Arai, Director at MMC, spoke about “MMC’s Activities”; Dr.
Tokio Kitahara, Professor at Shonan Institute ofTechnology, spoke about “Features of Micromachines”; and Mr. Tsuneji Yada, General Managerof the Information Department at MMC, spoke
about “An Outline of the Second Phase of theMicromachine Project”.
The seminar also included the following presentations on results of the Industrial Science
Technology Frontier Project.

A scene from the Oita Micromachine Seminar

A scene showing portable exhibit of micromachinetechnology“Development of Microconnector”
Mr. Tsuyoshi Haga (SUMITOMO ELECTRIC
INDUSTRIES, LTD.)“Development of Microgyroscope”
Mr. Hiroshi Kawai(MURATA MAUFACTURING CO., LTD.)“Micropump”
Mr. Takashi Kawano(AISIN COSMOS R&D CO., LTD.)“Micro Servo Actuator”
Mr. Hiroshi Nakamura(YASKAWA ELECTRIC CORPORATION)
The seminar was brought to a close in a great
success with the closing address by Tatsuo Sato,
Chief Researcher at the Oita Industrial ResearchInstitute.
A high degree of interest was expressed in thisseminar, with 43 participants from 30 companies
in Oita Prefecture and Kumamoto Prefecture related to precision machinery, displays, laser processing industry and semiconductor processing,
together with 17 participants from universities,
research institutes and public organizations, giving a total of 60 participants. Lively question andanswer sessions took place about the content of
the addresses, making it a highly meaningful seminar.

Sixth Micromachine Drawing Contest
Award Ceremony Held
The Micromachine Drawing Contest sponsored by theMicromachine Center (MMC) for elementary and junior highschool students was held this year for the sixth time. Pupils
from 23 elementary and 12 junior high schools in Amagasaki
and Itami (Hyogo), Hirakata (Osaka), Kariya (Aichi), Ina(Nagano), Nakai and Kawasaki (Kanagawa), Narashino(Chiba), Tsukuba (Ibaraki), and Shizukuishi (Iwate) entered
this year’s contest. The contest was conducted with the cooperation of MMC’s supporting members SANYO Electric Co.,
Ltd., Matsushita Research Institute Tokyo, Inc. and
MITSUBISHI ELECTRIC CORP., as well as the Science Museum in Tokyo.
This year’s contest garnered an all-time record of 3,215
entries, 1,511 in the elementary school category and 1,704 in
the junior high school category. The participating schools wereas follows.

The participating schools
Elementary Schools:
Sonoda-kita Municipal Elementary School (Hyogo Prefecture)
Sonoda Municipal Elementary School* (Hyogo Prefecture)
Sonoda-higashi Municipal Elementary School (Hyogo Prefecture)
Kamisakabe Municipal Elementary School (Hyogo Prefecture)
Sonowa Municipal Elementary School (Hyogo Prefecture)
Ozono Municipal Elementary School (Hyogo Prefecture)
Koyanosato Municipal Elementary School (Hyogo Prefecture)
Nakamiya-kita Municipal Elementary School (Osaka)
Iura Municipal Elementary School (Aichi Prefecture)
Fujimatsu-minami Municipal Elementary School (Aichi Prefecture)
Futaba Municipal Elementary School (Aichi Prefecture)
Sumiyoshi Municipal Elementary School (Aichi Prefecture)
Kotakahara Municipal Elementary School (Aichi Prefecture)
Fujimatsu-higashi Municipal Elementary School (Aichi Prefecture)
Ina Municipal Elementary School (Nagano Prefecture)
Inokuchi Municipal Elementary School (Kanagawa Prefecture)
Nakamura Municipal Elementary School (Kanagawa Prefecture)
Mita Municipal Elementary School (Kanagawa Prefecture)
Okubo-higashi Municipal Elementary School (Chiba Prefecture)
Namiki Municipal Elementary School (Ibaraki Prefecture)
Shizukuishi Municipal Elementary School (Iwate Prefecture)
Science Hall Received (Two)

Junior High Schools:
Sonoda-higashi Municipal Junior High School (Hyogo Prefecture)
Sonoda Municipal Junior High School (Hyogo Prefecture)
Karigane Municipal Junior High School* (Aichi Prefecture)
Kariya-minami Municipal Junior High School* (Aichi Prefecture)
Kariya-higashi Municipal Junior High School (Aichi Prefecture)
Isami Municipal Junior High School (Aichi Prefecture)
Asahi Municipal Junior High School (Aichi Prefecture)
Fujimatsu Municipal Junior High School (Aichi Prefecture)
Nishiminowa Municipal Junior High School (Nagano Prefecture)
Nakai Municipal Junior High School (Kanagawa Prefecture)
Minamiikuta Municipal Junior High School (Kanagawa Prefecture)
Takezono-higashi Municipal Junior High School (Ibaraki Prefecture)* School prize awarded.

Dr. Keiko Nakamura, Deputy Director General, Biohistory
Research Hall
Dr. Ryoze Yamashita, Associate Professor, Tokyo National
University of Fine Arts and MusicMr. Takayuki Hirano, Executive Director, Micromachine Center
The award ceremony was held on March 28 at the
KASUMIGASEKI TOKYO KAIKAN on the 35th floor of theKasumigaseki Building in Tokyo. It was attended by some 50
persons, including the best entry prize and the first prize winning pupils, school members, guests, and the juries.
At the award ceremony, Mr. Yoshikazu Yamaguchi, Director for Machining and Aerospace R&D, AIST, MITI made aspeech to the children after explaining easily why the researchand development of micromachines is needed. “It will take more
and more times for practical application of such technology, so
I hope this contest proves to be a springboard for at least one
or two of you to someday enter the fields of science, technology,
or research and development not only in micromachines.”
Professor Miura, the Chief of the jury, reported on the judging process and commented on the work submitted. He said,“In this contest, incidentally, both of two Best Entry Prizes havethemes of environmental problems in society, and both of two
First Prizes are drawings of IT (Information Technology)-related applications. I have been impressed that the children have
got well the need change in the era. I have pleasantly judged
as well as I have been made consider them.”
Following the introduction of the selected drawings, testimonials and prizes were awarded to Kaori Matsui (6th graderof Futaba Municipal Elementary School in Aichi Prefecture)in the elementary school category and Takashi Suzuki (3rdgrader of Kariya-minami Municipal Junior High School in Aichi
Prefecture) in the junior high school category. In addition, theelementary and junior high schools that submitted the mostsubmissions received school awards.
After receiving the award, Mr. Suzuki expressed his will
for the future: “Now, through this contest, I’ve been impressedby the great possibility of micromachines, and at the same timerealized it depends completely on human’s creative ideas
whether utilizing the possibility or not. I will also make myefforts to get much creative ideas since now.”
After the ceremony, six portable micromachine technology
exhibits were displayed at the hall. The children and their parents and teachers alike crowded around the exhibits, their eyes
gleaming in wonder at the first actual micromachines they had
ever seen.

A jury listed below selected 15 artworks from the elementary school category and 15 from the junior high school category. The selected artworks are shown on the following pages.
Jury
Dr. Hirofumi Miura (Chief), Professor, Kogakuin University
Dr. Naotake Ooyama, Director-General, Mechanical Engineering Laboratory, Agency of Industrial Science and Technology,
MITI

Commemorative photograph of award winners

11Winners of the Sixth Micro
Elementary School Category:
Best Entry PrizeFirst Prize

Second Prize

Water cleaner for home use, With compost maker

Ring-type cellular phone

Little MM nurses,
Pichi and Minya

Yuki Terada
Nakamiya-kita Municipal Elementary School (6th grade)
Asuka Nakamura
Ina Municipal Elementary School (4th grade)
Kaori Matsui
Futaba Municipal Elementary School (6th grade)

Third Prize
MM Cleaner

Second Prize

Third Prize

Third Prize

ThreaderMr. Drain-pipe Cleaner

Science machine

Aya Katsurasako
Sonoda Municipal Elementary School (6th grade)

Rei Itoh
Nakamiya-kita Municipal Elementary School(6th grade)

Daiki Furuya
Inokuchi Municipal Elementary School(4th grade)

Honorable Mention

Honorable Mention Honorable Mention Good Idea Mention

Rescue machine 181

Mr. Stain Remover

Takahiro Kodama
Mihoko Ushiroda
Nakamiya-kita Municipal Elementary School (6th grade) Fujimatsu-higashi Municipal Elementary School(6th grade)

Good Idea Mention
Responding machine tocontact lensKana Kobayashi
Sonoda Municipal Elementary School (5th grade)

12

Hiromasa Tsukamoto
Fujimatsu-minami Municipal Elementary School (4th grade)

Cleaner snail

Landmine detector

Saki Hazama
Nakamiya-kita Municipal Elementary School(6th grade)

Yoshitaka Ohta
Sonoda-higashi Municipal Elementary School(4th grade)

Good Idea Mention

Effort Mention

Effort Mention

Do-anything machine

Communicator machine

Beauty saloon for pets

Yoshiaki Ohsawa
Fujimatsu-higashi Municipal Elementary School(5th grade)

Sakurako Hirahara
Nakamiya-kita Municipal Elementary School(6th grade)

Ken Itoh
Ina Municipal Elementary School (4th grade)machine Drawing Contest
Junior High School Category:
Best Entry PrizeFirst Prize

Second Prize

Rescue machine for mountaineering
accidents

Any language is OK, Mini Japanesetranslator

Safety eye

Takafumi Suzuki
Kariya-minami Municipal Junior High School (3rd grade)

Nozomi Mimura
Sonoda Municipal Junior High School (3rd grade)

Syoko Ohno
Kariya-minami Municipal Junior High School (3rd grade)

Second Prize

Third Prize

Third Prize

Third Prize

Stimulating cap for antiforget-fulness

Dot character readingmachineAnti-arteriosclerosis
machineHuman detector after
disasters

Izumi Kaneko
Nakai Municipal Junior High School (3rd grade)

Masahiro Hara
Nakai Municipal Junior High School (3rd grade)

Tae Suzuki
Nakai Municipal Junior High School (3rd grade)

Yukari Tomikawa
Karigane Municipal Junior High School(3rd grade)

Honorable Prize

Honorable Prize

Honorable Mention

Good Idea Mention

MM ladybug

Emergency notifier

Vacuum-and-burn typeanti-virus MM

Seeking and fixing machine
for landmines

Kayoko Sugiura
Katsuhiro Ogawa
Karigane Municipal Junior High School (3rd grade) Kariya-minami Municipal Junior High School(3rd grade)

Good Idea Mention

Good Idea Mention

Rocket repairing machine

Mini-mini barber

Keigo Bove
Nakai Municipal Junior High School (3rd grade)

Akane Ohsera
Sonoda-higashi Municipal Junior High School(3rd grade)

Atsushi Tsuchiya
Karigane Municipal Junior High School(3rd grade)

Effort Mention

Effort Mention

Instantaneous translating
earring

Ready detector

Yuki Kondoh
Kariya-minami Municipal Junior High School(3rd grade)

Arisa Ohashi
Sonoda Municipal Junior High School(3rd grade)

Mizuho Koshimizu
Nakai Municipal Junior High School (3rd grade)

13

AISIN COSMOS R&D
CO., LTD.
1. The challenge of Micromachine Technology
With micromachines being considered a basic technology highly likely to revolutionize automobile partsand life-related equipment in the field of business of
AISIN SEIKI CO., LTD. the company is emphasizing
the research and development of this technology. For
the past five years, the company, aiming at accumulating micromachine-related basic techniques, has focusedits research on miniaturizing elemental functional parts.
In the process of this research and development, theadvantages of the micromachine technology, along with
its commercialization, have been unveiled. This has convinced the company research and development toward
the commercialization of this technology on the basis of
the techniques accumulated so far is essential in the
future. It is therefore necessary to deal with the miniaturization, improvement of reliability and durability, andcost reduction of the equipment in question. The company intends to promote its research and development
activities so that it can put its products on the market
at an early date.
2. Development of Micromachine Technology
The company has been accumulating basic maicromachine techniques through the research and development of miniaturizing micropumps that move in a wormlike manner with laser light energy. This peristaltic
micropump, mounted on the tip of a micromanipulator,
is used for ejecting trace amounts of adhesive when assembling microparts in the microfactory system. Within
this research and development are incorporated manytechnical development factors that constitute the subject of miniaturizing elemental functional parts for controlling viscosity and for supplying heat and energy (SeeFig. 1). This research and development is expected todeepen the understanding of micromachine technology.
This has prompted the company to develop a large displacement diaphragm, a light actuator utilizing liquid
phase changes, light actuator arraying, and a light

President Masami Inada

waveguide with the added function of radiating laser
light outside the plane. The company is now in the stageof verifying the functioning of a laser-driven micropump
prototype (Fig. 2) and carrying out the research on how
to advance the technology to a higher degree. Particularly worthy of note is that the micropump has beenminiaturized with the peristaltic mechanism employed
and that it has enabled the feeding of liquid continuously and bi-directionally and the discharging of a trace
amount of adhesive with the loss of pressure in the liquid path properly controlled. At present, the pump partof the light-driven coating device, 3.5 × 1.8 mm in section and 14.5 mm in length, has been confirmed to beable to coat adhesives to a level of some 10 nl.

Micropump

Fig. 2 Light-driven Coating Device

Diaphragm

Laser beam ON

Optical energy

Fig. 1 Principle of Peristaltic Micropump

14

Fig. 3 How Trace Amounts of Adhesive are Discharged

3. Future StanceIn recent years, micromachine technology has
emerged from the initial field of microsensors to a larger
field of fluid-related applications. However, the company
intends to further perfect the techniques it has accumulated so far, including micropump techniques andthose directly related to market-needs-oriented products.

OMRON Corporation
1. The challenge of “Micromachined Sensing”
As society becomes increasingly diversified andindividualized, control components such as sensors
and relays are required to be not only smaller insize but also to have capacities that satisfy various needs. Omron’s micromachined sensing is
aimed at pursuing the potential of semiconductors
as sensors and relays, and forming micro mechanisms in the order of microns, which may be called“intelligent structures,” onto chips. This technology should satisfy the need for device downsizing,
and also be of considerable value to every aspectof industry, society, and daily life. Omron has already developed MEMS (Micro Electro Mechanical Systems) products such as electrostatic acceleration sensors, pressure sensors, and micro lensarrays using micromachining techniques based on
IC fabrication process technology. They have been
incorporated into products such as sphygmomanometers.
2. Development of Micromachine Technology
As part of the research and development of advanced technology, the Industrial Science and Technology Frontier Program called “Research andDevelopment of Micromachine Technology” is dealing with the research and development of opticaltechnology, a fusion of MEMS technology and optics. We have the objective of realizing a micro optical scanning type image sensor for measuring thesize of small cracks in generator turbine blades,
etc. in this project. To date, we have developed atwo-dimensional micro optical scanner using a 2degree-of-freedom vibrator, and a high-performance piezoelectric thin-film actuator to drive theManaging officer Tsukasa Yamashitascanner. Moreover, in order to miniaturize a recognition sensor (image sensor) with an opticalscanner, we have designed a multi-layer stacked
device structure in which different functional elements composing the sensor (the light source, micro optical elements, photo detector, and two-dimensional micro optical scanner) are placed on
their respective substrates, which are then stacked
into one piece. This has resulted in the realizationof a micro optical scanning sensor with external
dimensions of 2 mm × 4 mm × 3 mm (the size of agrain of rice). This sensor also has a distance-measuring function which, despite its very small size,
enables object size measurement with a resolutionof 0.5 mm or better in a measurement range of 50
mm ± 10 mm by using information on the image ofthe detected object and the distance to the object.
3. Future StanceIn the Industrial Science and Technology Frontier Program, we have been able to obtain basic
technology for the two-dimensional micro opticalscanner, a key device in the micro optical scanning sensor. Our future challenges include packaging technology and process development formass production. We aim to put the sensor to practical use and apply it to other uses.

A grain of riceFig. 1 Micro Optical Scanning Sensor

Fig. 2 Example of the Size Measurement

15

MEMS 2000 Report
The 13th MEMS international convention,
hosted by the IEEE Robotics and Automation Society and supported by the Micromachine Center,
was held at the Miyazaki Seagaia Convention Hallfor five days from January 23 to 27, 2000.
Four of the five days were allotted for the convention, which had 141 presentations in total, withthree invited lectures, 41 oral presentations, and97 poster presentations.
The number of applications (abstract applications) was a record high at 319, which demonstrates severe screening with an adoption ratio of
43%.
The numbers of presentations by country (excluding invited lectures) were: 48 from Japan and
45 from the US, followed by 9 from Switzerland, 8
from South Korea, 8 from the Netherlands, 7 from
China, 5 from Germany, 3 from France, 3 from Sweden, and 2 from Taiwan.
Of the 433 people registered in advance (registration list), their numbers by country were: 258
from Japan, 79 from the US, 25 from South Korea,
13 from Switzerland, 12 from the Netherlands, 9from Taiwan, 9 from Germany, 8 from China, andothers. The attendance from South Korea was noticeably high. The total attendance eventuallyreached 521. Many people from companies participating in the Industrial Science and Technology
Frontier Program “Micromachine Technology”
were also present and made six presentations asshown in Table 1.
According to the contents of the session program, there were 23 presentations related to electrostatic, piezoelectric, and other actuators, 21 presentations on sensor technology for pressure, acceleration, and gyroscopic sensors, 17 on micro-fluidics, 16 on opto-MEMS, 16 on novel technologies,
and others on 3D structures, biotechnology, bonding and packaging, materials and measurement,
modeling design, etc.
Of the 23 presentations on actuators, 9 wererelated to electrostatic actuators (5 of them dealing with switches, light, fluids, positioning stages
and others developed for specific applications), 7
on piezoelectric actuators (2 of them for their application to µ fluidics), 3 on SMA actuators (1 of16

Photo 1 Reception Party Scene

them for their application to catheters), 2 on pneumatic actuators, 3 on polymer actuators, 1 on electromagnetic actuators, and 1 on other topics. (Thepresentations falling under more than one field
are counted more than once.)
Of the 21 presentations on sensors, 6 were on
acceleration/gyroscopic sensors, 4 on pressure sensors, 2 on flow sensors, 3 on heat sensors, etc.
There were 17 presentations on micro-fluidics,
with 2 on micropumps, 2 on micropipettes, 2 on
micro integrated fluid devices, and 1 on each ofvalves, thrustors, mixers, and diffusers, respectively.
The application session included presentations
on AFM, spectrometers, acoustic devices (two presentations), microrelays (two presentations), andink-jet printers. Researches in mechanical fields
were also presented, ranging from micro flightmechanisms (two presentations), decelerators,
catheters, and microrobots to displacement magnification mechanisms.
Moreover, at the lobby in front of the lecture
hall, the Micromachine Center exhibited trial systems, and Denso, Sanyo Electric, Sumitomo Electric, Yokokawa Electric, Yasukawa Electric, andMitsubishi Cable Industries each displayed panels to present their researches.
On the evening of the first day, a reception washeld at the Seagaia Ocean Dome next to the hall
(Photo 1). It was a buffet-style party in a restau-

Photo 2 Banquet Scene

rant facing a beach washed by artificial waves.
Participants were requested to wear bathing suits,

in principle, and they enjoyed swimming in thesea, a dance show with a tropical flavor, and a demonstration by surfers. During the party, college
professors, executives of participating companies
and many other participants deepened relationships with one another, and this arrangement of
the party really helped to make their personal relationships closer. The party ended with a lasershow using fountain water as projection screen andbroke up as participants left.
On the night of the third day, a grand banquet
was held in a rearranged lecture hall (Photo 2).
There were attractions such as Yamatodaiko drumming and rice cake making, and an introduction
to Interlaken in Switzerland, the next venue.
The next convention will be held from January
21 to 25, 2001, and the deadline for abstract applications will be August 15, 2000.

Table 1 Research results from the Industrial Science and Technology Frontier Program“Micromachine Technology” presented in MEMS2000(1) “Ultrasonic Micromixer for Microfluidic Systems” (POSTER SESSION)
Z. Yang, H. Goto, M. Matsumoto, and R. Maeda / Mechanical Engineering and OMRON Corp.
(2) “Optimization of Mechanical Interface for a Practical Micro-Reducer” (POSTER SESSION)
H. Takeuchi, K. Nakamura, N. Shimizu, and N. Shibaike / Matsushita Research Institute Tokyo,
Inc.
(3) “Profile Measurement of High Aspect Ratio Micro Structures Using a Tungsten Carbide Micro
Cantilever Coated with PZT Thin Films” (POSTER SESSION)
M. Yamamoto*, I. Kanno**, and S. Aoki* / *Matsushita Research Institute Tokyo, Inc.,**Matsushita Electric Industrial Co., Ltd.
(4) “Torque Measurement Method Using Air Turbine for Micro Device” (POSTER SESSION)
H. Ota, T. Ohara, L. Luming, M. Takeda, H. Narumiya, and K. Namura / MITSUBISHI ELECTRIC CORPORATION(5) “A New Smart Vision System Using Quick Response Dynamic Focusing Lens” (POSTER SESSION)
T. Kaneko, N. Mitsumoto, and N. Kawahara / DENSO CORPORATION(6) “Development of Chain-Type Micromachine for Inspection of Outer Tube Surfaces (Basic Performance of First Prototype)” (ORAL SESSION)
M. Takeda*, K. Namura*, K. Nakamura**, N. Shibaike**, T. Haga*** and H. Takada*** /*Mitsubishi Electric Corp, **Matsushita Research Institute Tokyo. Inc, ***SUMITOMO ELECTRIC INDUSTRIES, LTD.

17

Latest Micromachining
Technology — Part 1
Shaping by Etching — Bulk Micromachining
Professor Kazuo Sato
Graduate School of Engineering, Nagoya University

In this four-lecture series beginning with this issue, we will
outline the latest machining process technology aimed at
micromachining. The entire series, including this lecture, iscomprised as follows:(1) Shaping by etching – bulk micromachining(2) Forming 3-D structures of thin films – surface micromachining(3) Pursuing finer machining – precision machining technology(4) Mass production by transferring shape – fine-molding technology
Micromachines have already come into use in the form ofdevices that are familiar to us, such as ink-jet printer heads
and video projector devices. These devices have been realized
by micromachining technologies. The above (1), (2), and (4) technologies have achieved great success in industrial use becauseof their features of integrated manufacturing processes, suchas precise arrangement of numerous micro-mechanical elements and mass production of products of uniform quality. The
subject of this lecture: “bulk micromachining” is a technology
to be contrasted with the next subject “surface micromachining.” This is a process technology for creating structures
on work material substrates (bulks) by etching.

2. Utilization of Etching Characteristics
There are isotropic and anisotropic etching characteristics,
which result in major differences in machined cross sections.
In general, when etching is begun at a mask opening, machining proceeds in the direction normal to the surface and affects
the lower part of the mask. This is called side etching or undercutting. If the supply of etching agents (etchants) and the discharge of reaction products are performed smoothly, and work
materials are homogeneous and isotropic, the amount of side
etching approximately equals the etching depth. This kind ofsystem is known as isotropic etching. A typical cross section
resulting from such etching is shown in Fig. 1. In isotropic etch-

1. Classification of Etching Methods
Etching is a process in which an etching mask is placed on
the surface of the substrate to be machined, and a minute opening pattern is formed in given regions of the mask by photolithography to selectively remove substrate materials according
to the pattern. Table 1 shows specifically what agents are used
to remove substrate materials.

ing, deep machining will cause mask pattern information to belost. Therefore there are limitations to its application to themachining of such structures as micromachines, but it is useful for limited purposes. For example, isotropic etching proceeds in all directions at the same rate, which allows minuteconcave surfaces to be machined when the etching is performed
from a mask with dot-shaped openings (see the left of Fig. 1).
An example of the utilization of this characteristic is ultrasonic microscopic concave lenses formed on single-crystal silicon. On the other hand, sharp points can be created if etching
is begun on the periphery of a disk-shaped etching mask andis stopped when the undercut has reached the center of the
disk. An example of the utilization of this characteristic is electron emitting cathodes.

Table 1 Etching Methods and Classification of Agents
Wet etching Acid: (example) hydrofluoric acid, nitric acid
Alkali: (example) KOH, ammoniac agents
Dry etching Gas:
(example) XeF2, BrF3
Radical: (example) F
Ion:(example) Ga, Ar, Cl, fluoro-carbon
Atom: (example) Ar
Among wet etching and dry etching agents, highly reactive
gases, radicals, and ions react chemically with substrate materials to remove them. On the other hand, low reactive ions andatom beams physically remove materials by hitting the surface of the substrate after the particles are accelerated. Thus,
etching has various mechanisms to remove materials, so that
etching characteristics are also varied as described below.

Mask

Workpiece

Fig. 1 Cross Section Resulting from Isotropic Etching

Mask

Workpiece

Workpiece

(a)

(b)

Fig. 2 Cross Section Resulting from Anisotropic Etching18

In contrast to isotropic etching, the etching characteristics
involving minimized side etching and deep machining from anarrow mask apertures are known as anisotropic etching. A
typical cross section resulting from such etching is shown in
Fig. 2. Since this etching enables deep machining according tomask pattern information, it is generally suitable for machining micromachine devices. Its realization requires special consideration to be given to the combination of work materials
and etchants, and other machining conditions. Dry processes
and wet processes have both contributed to major advances incharacteristic anisotropic etching techniques over the past several years.
A typical method of anisotropic dry etching is reactive ion
etching (RIE). Fluoric gases such as CF4 and SF6, for example,
are introduced into a vacuum chamber, and a high-frequency
voltage is applied between the electrodes to generate plasma,priority is then given to the execution of etching in the direction normal to the silicon substrate. In micromachine research
applications, the use of high-density plasma by means of inductive coupling type equipment (ICP) has recently allowed
machining with an etching depth of 300 to 500 µm at an aspectratio of 15:1 to be performed at an etching rate of 5 µm/min.
Fig. 3 (a) shows a cross-sectional photograph of the step hole ofan ink-jet printer nozzle machined by this method. The smaller
opening is 28 µm in diameter.

(a)

(b)

Fig. 3 Examples of Machined Ink-Jet Printer Heads(a) Nozzle Hole Machined by Dry Etching(b) Ink Reservoir Machined by Wet Etching(Both by courtesy of SEIKO EPSON CORPORATION)
Among the anisotropic wet etching methods, on the other
hand, there is chemical anisotropic etching which uses theanisotropy of the work material itself. Since the equipment
necessary for this machining is inexpensive, it is used with afar higher degree of frequency than dry etching for the production of practical devices. The silicon single crystal has a diamond crystal structure, and causes the etching rate to differ
by as much as 100 times depending on its crystal orientation,
showing strong anisotropy. This results in a unique three-dimensional etched shape reflecting its crystal structure; in otherwords, polyhedral structures as shown in Figs. 2 (a) and (b)can be readily obtained. KOH aqueous solutions, tetramethyl
ammonium hydroxide (TMAH) aqueous solutions, etc. are
known as its etchants. Fig. 3 (b) shows a cross-sectional photograph of a printer ink reservoir etched with a KOH aqueous
solution. Each compartment is uniformly etched, leaving the
2.2 µm-thick diaphragm at the bottom for pumping operation.
Moreover, etching performed from the top and bottom surfacesof the silicon substrate will result in a more complex threedimensional structure. Fig. 4 is an example of curved surface
machining performed at the base of a silicon beam used in an

Fig. 4 Example of Curved Surface Machining by Chemical
Anisotropic Etching

acceleration sensor. Chemical anisotropic etching, which has
been thought to be performed only on polyhedrons, has allowed
a smoothly curved three-dimensional surface to be realized. Inorder to machine complex three-dimensional structures suchas the one shown in this example, a few etching processes using the same number of different mask patterns, rather than
only one etching process, are required. The relation between
the crystal orientation of the substrate and mask shape as wellas the composition of the etching solution and the temperature determines the finished shape. Etching simulation systems and databases on the etching characteristics of silicon,
which enable such process design, have recently been developed and put to practical use.
Crystal anisotropic etching can be performed not only on
silicon single crystals, but also on other crystal materials suchas quartz and GaAs.
3. Comparison of Wet and Dry Etching
The advantages and disadvantages of dry and wet etching
are compared with respect to several items, which is shown in
Table 2. The type of etching to be applied will depend on themachining characteristics required, and in industrial applications, returns on plant and equipment investments must be
considered. In micromachine development, the selection of an
etching method directly affects device design, so that the machining techniques you have determine the types of devices
you can manufacture. In other words, micromachine device
development requires a concurrent type of development system that integrates design with machining.
Table 2 Comparison of Dry and Wet Types of Anisotropic
Etching (+: superior, –: inferior)
Machining fineness
Cleanliness, ease of integration
with electronic circuits
Etching with given twodimensional patterns
Etching depth controllability
Etching depth uniformity
Machining of special shapes
Equipment costs required
for machining

Wet etching Dry etching
+
++
–
++
–––

+++

++
++
++
+++

+
–
+
––

19

Preliminary Announcement
The 6thInternational
Micromachine Symposium
November 9 and 10, 2000
at Science Hall, Science Museum, Tokyo, JAPAN

Exhibition

MICROMACHINE2000
November 8 - 10, 2000
at Science Museum, Tokyo, JAPANThe Detail will be announced later.

:

Pictures on the cove
coverr Winning artworks in the Micromachine Drawing Contests
Bee-type robot, Navigator for vision handicaps, 3-dimentional robot “Ant”, and Take-it-all (from top to bottom)

MICROMACHINE No. 31
MICROMACHINE is published quarterly by Micromachine Center (MMC) to promote the international exchange of
information related to micromachines, R&D and other technical topics, and is circulated free of charge. Please send
your comments about MICROMACHINE to the publisher:
Takayuki Hirano, Executive Director, Micromachine Center (MMC)
5-F, Niikura Building, 2-2, Kanda-tsukasacho, Chiyoda-ku, Tokyo 101-0048, Japan
Tel: +81-3-5294-7131, Fax: +81-3-5294-7137
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Change of Address: Please send old address label and new address to the publisher.
Editorial and Production Management: Japan Technical Information Service (JATIS)
Date of Issue: May 29, 2000
© All Copyrights Reserved by MMC

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