Essay

Micromachine Technology
Reaches a New Stage
Toshiro Shimoyama
Chairman,Micromachine Center

March 31, 2001 saw the conclusion of the decade-long
Micromachine Project, part of the Industrial Science andTechnology Frontier Program sponsored by the Ministryof Economy, Trade, and Industry. I would like to take thisopportunity to thank the many people from thegovernment, private industry, and academic sectors who
have been involved with the Project over the last ten
years in a research and/or surveying activity. I would also
like to extend my appreciation to all those at the Ministryof Economy, Trade and Industry (formerly the Ministry ofInternational Trade and Industry) in recognition of theirsupport for the Project.
When this Project was launched in 1991, Japan wasembroiled in commercial difficulties in the form of trade
friction over semiconductors, as well as criticism that itwas "freeloading" by benefiting unfairly from the research
investment of other nations. The Micromachine Project
was an attempt to give Japan an independent research
capacity in this area via a completely new approach toresearch that had never been tried elsewhere. The firstphase involved identifying key technology concepts bydeveloping element technology predicated on the idea ofmachines at the micro level, once the sole preserve of
science fiction (such as the movie Fantastic Voyage). The
second phase involved the study of systematization
technology for integrating the various forms of element
technology into machine systems. Overall, the Project was
remarkably successful, generating some 530 patentapplications and 1,500 research publication papers andpresentations (mainly to academic societies).
The Micromachine Project attracted considerable
interest from overseas, particularly with respect to its
unique approach to industrial research. Many academic
groups came to Japan to see the Project. Researchers andexperts in Japan and overseas were most impressed. In
addition, the Project enjoyed extensive coverage in theworldwide media and became well known in wider society.
Last year's Exhibition MICROMACHINE 2000, whichfeatured broadcasts of an experimental prototype systemon five programs (including one from the publicbroadcaster NHK), was the first important step in
addressing the national problem of the continuing drift ofyoung people away from science subjects. Despite the ten
years lost to the continuing economic downturn, theMicromachine Project has brought Japan closer to theideals of micromachine technology, which is expected toplay a central role in the basic "manufacturing" technology
in 21st century.
The Micromachine Center (MMC) was established at
the same time as the Micromachine Project with the aimof promoting the technology and providing informationworldwide via a range of initiatives. With the conclusion of
the Project, micromachine technology has reached a newstage. The first task for us now is to speed up the processof refining the technology to create viable industrial
applications. Many other nations, inspired by the work of
the Project, are building the necessary infrastructure fordesign, prototype trials, and production for thedevelopment and manufacturing of MEMS. Meanwhile,
the MMC is working on practical development in thetechnology field created through the fusion of
micromachine technology and the advantages of MEMS.
The second task is to take up the challenge presented by
new research areas within the context of nano-technology
development around the world.
The nano-technology represents the great unexplored
field and the most important branch of technology in the
21st century. This was acknowledged last year when thenpresident Bill Clinton announced a budgetary allocation of$500 million towards nano-technology development.
Nano-technology is a genuinely revolutionary area
involving the manipulation of materials at the atomic andmolecular level to enable, for instance, the manufacture ofmaterials that are lightweight yet ten times stronger thansteel and the detection of cancer cells at a very earlystage. But even the most spectacularly advanced nanotechnology is not truly useful unless it is complemented
by a human interface that appeals intuitively to our basic
senses-in other words, human-sized technology isrequired as well. Micromachine technology provides thebridge, the vital link between nano-technology andhuman-sized technology. The Micromachine Center iscommitted to pursuing viable industrial applications for
micromachine technology (as described above), while also
working to further refine and integrate micromachinetechnology into nano-technology fields.
The Micromachine Center looks forward to yourcontinued patronage and support in the years to come.

2

Worldwide R&D

Microsystems Based on the
Biological Functions of Insects
Isao Shimoyama
Professor,
Department of Mechano-Informatics, graduate School of Information Science and Technology, The University of TokyoAt our laboratory, we are studying on new machinery
systems in an interdisciplinary research field between
engineering and biology : micromachines, robotics andneuroethology. We are particularly interested in the creation of
microsystems modeled on the biological functions of insects andmicro-devices designed to help us learn more about biological
functions. This article describes some of our main research
projects.
Microsensors modeled on the biological functionsof insects
We have developed a visual sensor modeled on thecompound eyes of insects. Figure 1 shows the visual sensor
system consisting of a micro-lens array, a photo-diode array, andan electrostatic microactuator. It is known that insects recognize
objects with the aid of minute oscillations of the retina. The
visual sensor produces the same effect as the oscillating retina of
the insect by scanning the visual axis through oscillating slits
operated by the actuator. Significantly, the sensor can be madeno thicker than a sheet of paper, making it eminently suitable forthe flexible visual devices of the future.

Fig.2 Flow velocity sensor modeled on sensory hairs

Micro-devices for recording biological signals
We are also studying micro-devices for measuring
neuroelectric and myoelectric potential in living organisms. We
have successfully measured changes in electrical potential on thesurface of an insect nerve cord of approximately 100µm diameterby holding it in a micro-electrode clip made of thin-film shapememory alloy (see Figure 3). We are currently developing awireless telemetry system for mounting on the actual insect that
can transmit measurement data back from the electrode.
By integrating the various systems described above, we will
be able to measure biological information from an insect without
imposing any restriction on its movement or behavior. We areconfident that this technology will significantly boost our
understanding of the mechanisms underlying insect behavior.

Fig. 1 Visual microsensor modeled on a compound eye

Crickets and cockroaches have thin sensory hairs on a pair oforgans extending caudally from the abdomen. Air flow aroundthe insect deflect the sensory hairs, generating mechanicaldistortion at the base of the hairs which is converted toneurosignals. Figure 2 shows the fabricated air flow sensor
modeled directly on this principle. A metal wire is fixed to thecenter of a supporting cross-beam structure. Movement in thesurrounding air causes the wire to bend, generating distortion at
the fixed ends of the beams. The distortion is detected bysemiconductor strain gauges. We are currently trying to integrate
multiple sensors. Similar sensory hairs can be found insidehuman organs such as the semicircular canals of the inner ear.
We are also developing a sensor based on this principle.

Fig. 3 Microelectrodes for insect neural recording

3

MMC Activities

Activities of the Micromachine Center in Fiscal 2000
I. Investigations and Research on Micromachines
1. The AIST Industrial Science and Technology Frontier Program"Micromachine Technology" (delegated to MMC by the New Energy
and Industrial Technology Development Organization [NEDO])

5. R&D on Micromachine Materials (joint research with the
Mechanical Engineering Laboratory of AIST)The following activities were conducted: (1) Research on the operating environments
for micro-functional elements; (2) research on micromachine materials; and (3) feasibility
studies on micromachine materials.

To achieve the goal of the basic plan for R&D (Phase II), research delegated to MMC
was actively promoted after pre-final evaluation of this project.

6. Investigation of R&D Trends in Micromachine Technology inJapan and Abroad(1) Development of Advanced Maintenance Technologies for Power
Plants

Review surveys of the latest development centering on international conferences.

q R&D of systematization technology (Experimental wireless micromachines for inspection
on inner surface of tubes)
A final experimental system was produced. In metal tubes with curved sections, thissystem is able to move forward, backward, horizontally and vertically, stop optionally, andrecognize its surroundings, as well as detect tube defects.
w R&D of systematization technology (Experimental chain-type micromachines forinspection on outer surface of tubes)
R&D of systematization technology was conducted through the production of anexperimental micromachine system composed of a group of machines capable of combining
or separating according to the form of the object to be inspected.
e R&D of systematization technology (Experimental catheter-type micromachine for repair
in narrow complex areas)
R&D of systematization technology was conducted through production of anexperimental micromachine system capable of entering the equipment of various structuresand performing measurements or repairing minute internal flaws.
r R&D of functional device technologies
R&D was conducted to promote micronization, high performance, and multifunctionalization of functional devices with highly advanced micromachine technology.
t R&D of common basic technologies
R&D was conducted on common basic technologies such as technologies for control,
measurement, design, and evaluation necessary for realizing micromachine systems.
y Comprehensive investigation and researchComprehensive investigation and research of maintenance micromachines necessary
for maintaining future power plants was conducted.

7. Activities incidental to other Investigative R&D
Holding of R&D Section meetings, Investigative Research Section meetings, anddepartmental and general research meetings.

II. Collection and Provision of Micromachine Informationq Collection and storage of information and documents on micromachines
w Maintenance and expansion of the MMC library, with all information listed in a databasee Publication of a periodical, "Micromachine Index" (published 8 times in FY 2000)
r Publication of a newsletter (on research and administration trends and the like)t Methods for transmitting data via Internet homepages, such as database construction anddata management operations, were considered.

III. Exchange and Cooperation with Worldwide Organizations
Involved with Micromachines
1. Research Grants for Micromachine Technology (12 themes in total)
Six new themes and six themes carried over from FY 1999

2. Participation in International Symposiums and Dispatching Missions
q Participation in µTAS 2000(the Netherlands) and ISAP 2000 (Glasgow, the United
Kingdom) in May 2000
w Participation in SPIE 2000 Symposium (Santa Clara, U.S.A.) in September 2000
e Participation in IWMF' 2000 (Freibourg, Switzerland) in October 2000
r Participation in The 2000 ASME International Mechanical Engineering Congress &Exposition (Orlando, Florida, U.S.A.) in November 2000
t Participation in MEMS 2001 (Interlaken, Switzerland) in January 2001

3. The 6th Micromachine Summit (Hiroshima, April 10-12, 2000)
4. The 6th International Micromachine Symposium (November 9-10,
2000)(2) Development of Micro-Factory Technology
q R&D of experimental micro processing and assembly system
R&D was promoted on systematization technology, suggesting its effectiveness, bycompleting the production of the second experimental system for processing andassembling, capable of manufacturing models of small parts.
w Comprehensive investigation and researchComprehensive investigation and research was conducted on micromachinetechnology that is capable of performing leading investigative research, and that is expected
to be put to practical use in the field of production. In addition, MMC conducted joint
research with the National Institute of Advanced Industrial Science and Technology (former
The Electrotechnical Laboratory of AIST on enhancing the performance of micro-electronguns for beam processing.

Held at Tokyo Science Hall; jointly sponsored by MMC and the Japan Industrial
Technology Association.

(3) R&D on Micromachine Technology

The Round Robin Test started in FY 2000. In connection with this program, joint
research with the Mechanical Engineering Laboratory of AIST was conducted.

5. Overseas Seminars
q European Seminars in Poland, Austria and Switzerland in September 2000
w Asian Seminars in Malaysia, Singapore and Thailand in November 2000

IV. Micromachine Standardization
1. International Standardization Program for Assisting New
Industries "Standardization of Quality Characteristic Measurement
Evaluation for Micromachine Materials" (delegated to MMC by the
New Energy and Industrial Technology Development Organization[NEDO])

q Research on micromachine systems
In the medical field, R&D on miniaturization and the multi-functionality of micro-laser
catheters and micro-tactile sensor catheters was promoted. R&D was also conducted on
micro scanning imaging units.
w Comprehensive investigation and researchComprehensive investigation and research was carried out on the applications of
micromachine systems to the medical field. In conjunction with the AIST MechanicalEngineering Laboratory, MMC also conducted research on micromachine basic design andmanufacturing technologies.

2. R&D on Standardization
Consideration of the important elements, and the technological issues involved therein,of the Standardization Program established in FY 1998 has moved forward.

V. Dissemination of Information and Education about Micromachines
1. MMC published a public relations magazine, "MICROMACHINE" (published 4times in FY 2000, in both English and Japanese)

2. MMC held the 7th Micromachine Drawing Contest
3. MMC held Micromachine seminars within Japan (in Fukui on September

2. Investigative Research for the Development of Responses to theIndustrialization of Micromachine-based Systems (delegated to
MMC by the Japan Machinery Federation)

22,2000 and in Tokushima on February 9,2001)

4. MMC produced videos of the 6th Micromachine Summit, the 6th International

Business models for new businesses incorporating micromachine technology wereconsidered.

5.

3. Investigative Research for the Creation of Systems Incorporating
Next-generation Micromachine Technology (delegated to MMC by
the Mechanical Social Systems Foundation)

6.

Focusing on the industrial sector in particular, we considered the clarification of theroles required of government, academia and industry, and the development of strategies for
micromachine technology R&D.

7.

4. Investigation and Research on the Applicability of Emerging
Technology in Other Fields to Micromachine Technology
8.

Investigative research was conducted to search out emerging technology in various otherfields, to verify its applicability and fusion, and to contribute to its diffusion and promotion.

4

Micromachine Symposium, the 11th Micromachine Exhibition, and otherevents
MMC twice organized seminars presenting the results of "Research on the
Applicability of Emerging Technology in Other Fields to MicromachineTechnology in FY 1999" (in Tokyo on July 7,2000 and January 12,2001)
MMC hosted a workshop presenting the results of "Research Subjects forthe 6 th Micromachine Technology Research Grants (FY 1998)" on
September 26,2000
MMC assisted in the editing and publishing a booklet directed at high school
students entitled Industry Graph 2001 Number 189: Our Country's
Micromachine
MMC held the 11th Micromachine Exhibition on November 8-10, 2000 at the
Science Museum in Tokyo

The Research Reports under the 7th
Micromachine Technology Research Grant
academics and people in the industrial world.
Among the themes selected for the seventh (1999)
research grant, one 1-year research project and six 2-year
research projects carried over from fiscal 1998 have been
completed.
Turn the page for a summary of the research results.

This research grant program started inviting
applications in 1993 as a part of the independent activities
of MMC. The purpose of the program is to assist college
and university staff engaged in basic research on
micromachines, as well as to promote further developmentof micromachine technology and communication between

Subjects for the Micromachine Technology Reserch Grant
Research Project Selected for Fiscal 1999
Leader & Co-Worker

Subjects

PeriodCoordinate Measuring Machine Using a
Parallel Mechanism for Micromachine Parts

1 YearAffiliation

Subjects

PeriodProf. Masao Washizu

Department of Mechanical Engineering, Kyoto
University

Molecular Surgey of DNA based on Microsystems

2 Years

Prof. Kazunori Kataoka

Department of Matenals Science, Graduate
School of Engineering, The University of Tokyo

Research Assoc. Atsushi
HaradaDepartment of Matenals Science, Graduate
School of Engineering, The University of Tokyo

Structural Design of a "Chemical Nanomachine" Based on the Self-organization ofPolymers and Its Application to Targeting
Therapy

2 Years

Research Assistant Prof.
Tooru Ooya

School of Materials Science, Japan Advanced
Institute of Science and Technorogy

Study on Biomedical Micromachine Using
Biodegradable Supramolecular-Assembly

2 Years

Lecturer, Hiroshi Toshiyoshi

3rd Division, Institute of Industrial Seience, The
University of Tokyo

Micromachine System for Micro-optical
Smart Pixel Application

2 Years

Prof. Hiroyuki Fujita

3rd Division, Institute of Industrial Seience, The
University of Tokyo

Prof. Shigefumi Nishino

2nd Division, Institute of Industrial Science, The
University of Tokyo

Research Assoc. Kiyoshi
Takano2nd Division, Institute of Industrial Science, The
University of Tokyo

Experimental Study on Fluid Flow and Heat
Transfer inside Microchannels Utilizing
Micromachining Technology

2 Years

Prof. T. H. Barnes

Physics Department, University of Auckland, New
ZealandLow Noise Feedback Interferometry for
Micromachine Servo Actuators

2 Years

Assoc. Prof. Takaaki Oiwa

Affiliation
Faculty of Engineerring, Shizuoka University

Carried-Over Projects Selected for Fiscal 1998
Leader & Co-Worker

Application Guidelines for the 9th (Fiscal 2001)
Research Grant Themes on Micromachine Technology
1. Objective of the research grant

5. Qualifications

Basic research on basic technology, functional element
technology, and systematization technology for
micromachines

College or university faculties (professors, associate
professors, lecturers and research associates) who
belong to academic societies affiliated with theFederation of Micromachine Technology

2. Research period

6. Other

Theme A : April 2002 - March 31, 2003, orTheme B : April 2002 - March 31, 2004

(1) Total funding granted : Approximately 10 million yen(The upper limit for a single research project is 2
million yen for theme A, and 3 million yen for theme B.)(2) After the grant is decided, we may ask recipients tocarry out their research in collaboration with supporting
member enterprises of the Micromachine Center, as
one of the objectives of this project is to encouragecommunication between enterprises and academics.
(3) Contact : Research Department, Micromachine Center
Person in charge : Hodono
E-mail : hodono@mmc.or.jp

3. Application period, theme decision, and funding
grant date
Application period : July 10 - October 31, 2001
Theme decision : Middle of March 2002
Funding grant date : End of March 2002

4. How to apply
Send a fax requesting the application form to theMicromachine Center. Be sure to include your own fax
number or a fax number where we can contact you.
Micromachine Center Fax : +81-3-5294-7137

5

Coordinate Measuring Machine Using a
Parallel Mechanism for Micromachine Parts
Takaaki Oiwa
Associate Professor,
Faculty of Engineering, Shizuoka University
1. Introduction
As the formation of high-precision micro-parts having complex 3D
shapes is becoming feasible, there is increasing necessity to perform
precise 3D evaluations of such parts. Rather than using mechanisms
based on the conventional rectangular coordinate system, we proposed a
new 3D coordinate measuring machine (CMM) using a parallelmechanism in which active pairs are set in parallel with an output link.
In the present study, we will develop a small parallel µCMM using such amechanism. This paper will give a brief outline of this device and reporton the results of studies on the link layout, as well as the trialmanufactured prismatic links (struts).
2. Outline
Fig. 1 shows a conceptual diagram of the parallel µCMM, the basic
design principles of which are described below.
(1) A link mechanism consisting of a parallel mechanism with 3 degrees
of freedom (DOF) is used in place of the mutually orthogonal slide
mechanisms using the rectangular coordinate system.
(2) While the spherical joints are the basic form of reference for
conducting precise measurements, calibration is performed based on
displacement sensors built into the strut that measure the rotational
error of the joint.
(3) The link layout is designed as a retracting mechanism to improve themeasuring resolution in relation to the scale resolution. Therefore,
the mechanism is larger in relation to the measuring space.
(4) The link layout is optimized to eliminate the effects of joint
rotational error and error in the mechanism's parameters on
measurement precision.

stage radius, probe length, and position on the measuring space along
the Z-axis were set as design variables. Fig. 2 shows the layout of thelinks for the parallel µCMM based on this design. The actual size of theparallel µCMM is expected to be about 1/2-1/5 the dimensions given in
the diagram.

Fig.2 Link configuration after optimal design

4. Prismatic Links
Next, an outline will be given for the trial prismatic links. Fig. 3
shows a photo of the link. An inchworm mechanism having a layered
piezoelectric element was used as the actuator. The theoretical drive
resolution was set to 2nm or less. An advanced linear measuring unit
(scale) having a precision of ±0.1µm and a resolution of 2nm or less isalso built into the link. Velocities were measured when applying a load in
the form of weights having masses of 10-400g. From thesemeasurements, it is clear that the velocity is nearly proportional to thesize of the load, and the links have a thrust of more than 4 N per link.
Next, positioning with closed loop controlwas performed using themeasuring unit as a feedback sensor. The time required for performing a
10-µm step positioning process was within 0.1sec.

Actuator andlinear scale
Frame
Automatic probechanger(3D touch probe,
tools, etc.)

Spherical joint
Prismatic joint
Universal joint

Workpiece

Probe

Workspace: 20 x 20 x 20mm

Fig.1 µ-CMM using a parallel mechanism

Fig.3 Photo of the trial-manufactured prismatic link

3. Link Layout Design
The link layout was studied to reduce the effects of errors inparameters and joint rotation on movement of the probe in order tofurther improve measuring resolution. We used singular values in a
Jacobian matrix as a function for expressing the magnitude of the above
effect. For purposes of comparison, the radial position of the sphericaljoint on the base and the size of the measuring space (100 ◊ 100 ◊
100mm) were set equivalent to the conventional parallel CMM. The

5. Conclusion
As described above, we proposed a small 3D CMM employing aparallel mechanism of 3 DOF with the aim of measuring the dimensions
and geometric deviation of 3D parts, such as micromachine parts. The
link layout was designed and trial prismatic links were manufactured andevaluated. Future plans call for studying the effects of the elastic
deformation and rotational error in the joints unit on thermal
deformation of the links.

6

Molecular Surgery of DNA
based on Microsystems
Masao Washizu
Professor,
Department of Mechanical Engineering, Kyoto University
base sequence. Cutting occurs the moment the particles contact the DNA.
In Fig. 2 III), restriction enzymes are immobilized on the particles forrecognizing and cutting a specific sequence. In this case, cutting occurs
only when the particles contact the sequence to be cut (see Fig.2 III b).
3. Developing Microprobes for Molecular Surgery
In order to perform molecular surgery at a high resolution, wedeveloped a probe for molecularparticles
manipulation, as shown in Fig. 3. The Latex(1-3 µm in diameter)
probe is formed of a substrate having a
sharp point and three or more sphericalparticles fixed to the top surface of theprobe. By retaining the particles on the
Substrate
substrate independently by a laser beam,
Pointed tip
the probe is designed to push its pointed
tip, on which enzymes are immobilized, Fig.3 Microprobe for manipulating
molecules
on a desirable position and at a desirable
orientation. The probe is first manufactured as a cantilever structure by
performing Si anistropic etching on the substrate. The micro-particles arethen fixed to the substrate by a molecular linker, and the structure isbroken off at the root.
Fig. 4 shows an example for controlling the orientation of the probe.
By deflecting a single laser beam at a high rate of speed using agalvanometer mirror, each of the three particles are trapped through atime-division method. Translational and rotational movement of theprobe is then achieved by moving the micro-particles while maintaining
their relative positions to one another.
4. Conclusion
Micromachine technologies, such as micromachined electrodes andmicromachined probes, are powerful means for interfacing with themolecular nano-world and macro-world. Based on our current direction,
we anticipate breaking away from conventional biochemical methods, inwhich molecules are collected in a test tube base, and developing new
biotechnologies capable of performing deterministic manipulation on
specific molecules at specific positions.

1. Introduction
In recent years, research has intensified on µ-TAS and other such
systems that fabricate chemical systems to be integrated on a chip.
Although µ-TAS in its present state is not really micro-sized, the samples
are provided in an aqueous solution, that is, as a bulk sample. Hence, byfurther miniaturizing these systems, we should be able to develop an
ultimate chemical system capable of treating molecules individually. DNA
is thought to be the most suitable target for manipulation on themolecular level, because DNA molecules contain the fundamental
blueprints of life and can easily multiply molecules. In the present study,
we researched a method of "molecular surgery" for fixing a single DNA
molecule to a fixed surface in order to cut or otherwise alter the molecule.
2. Molecular Surgery of DNA
Just as a patient is fixed to an operating table in normal surgery, theDNA molecule, which is the target of our molecular surgery, must also be
fixed to a surface. It is also necessary to stretch the DNA molecule in a
linear shape in order to access the desired location. The author andothers developed a method using the electrostatic field in a
micromachined electrode to stretch the DNA and anchor the ends of themolecule. As shown in Fig. 1, enzyme cutting at a specified position isachieved by laser-manipulated micro-particles on which DNA-cutting
enzymes are immobilized.
Micro-particles with immobilized DNA-cutting
enzymes (DNase)
Micro-particles on which enzymes areimmobilized are retained by laser
manipulation and applied to a stretchedand fixed DNA molecule
DNase
Electrode
Stretched and fixed DNA molecule

Fig.1 Conceptual drawing of DNA molecular surgeryI) Mechanical cutting by
non-modified particlesa)II) Cutting by particles with III) Cutting by particles withimmobilized restriction enzymes
immobilized DNaseI
Particles with immoa) bilized DNasel

l-DNA

a)

b)

b)

b)

Electrode

Electrode

Electrode

15µm

l-DNA

d) Rotational movement to the right

Probe

Particles withimmobilized Hind III

l-DNA

Latex particlesa) Translational movement upward

15µmb) Translational movement to the righte) Translational movement to the leftc) Translational movement downwardf) Trajectory of the above movement

Electrode

15µm

Fig.2 Molecular surgery of DNA

Fig. 2 shows photos of the cutting operations. In Fig. 2 I), latex
particles on which enzymes are not immobilized are pressed against theDNA. Mechanical cutting does not occur until the DNA has stretched 1.5
times its natural length. In Fig. 2 II), DNaseI are immobilized on particles
that are pressed against the DNA for cutting the DNA without relation to its

10µm

Fig.4 Translational and rotational movement of the probe

7

Structural Design of a "Chemical Nano-machine" Based on the Selforganization of Polymers and Its Application to Targeting Therapy
Kazunori Kataoka, Professor,
Atsushi Harada, Research Associate,
Department of Materials Science, Graduate School of Engineering, The University of Tokyo
1. Introduction
The capacity to work effectively in microspaces is important in thefield of micromachine technology. Focusing from such viewpoint, there
are many kinds of available molecules in nature. Enzymes, for example,
serve as a biological catalyst that, when catalyzed under mild conditionsin an organism, can generate numerous organic reactions withphenomenal speed and selectivity. Hence, enzymes can be considered atype of natural micromachine. However, their use in vivo often limited
due to their instability and antigenicity. In particular, solving these
problems is a major issue in the field of site-specific enzyme delivery. In
this study, we prepared core-shell type multimolecular assembly
entrapping enzyme molecules in the core (see Fig.1), which were formed
from the mixture of charged block copolymer (polyethylene glycolblock-poly a,b-aspartic acid) with an enzyme (egg white lysozyme)
driven through electrostatic interaction in an aqueous solution. We
studied the utilities of the "chemical nano-machine" to perform
appropriate biochemical reactions under various conditions.
poly (ethylene glycol)-block-poly(a,b-aspartic acid)Egg white lysozyme

Bacterial cell
+NaCl
-NaCl

Lysozyme
ON state of enzymatic activity

Transmittance at 450
nm (%)

OFF state of enzymatic activity

60
50

NaCl 150mM

40

NaCl 0mM

30

NaCl 18.75mM

20
10

0

120

240

360

480

Time (sec)

600

720

Fig.2 On-off control of enzymatic activity synchronizing
with reversible formation by an external stimulus

the assembly, was used, and enzymatic activity was evaluated through themonitoring of the release amount of p-nitrophenol. Fig.3 shows the resultsof observing the generation of p-nitrophenol directly after combining the
enzyme by itself and entrapped in the assembly with the substrate solution.
These results showed that an enzyme reaction occurs even when the
enzyme is entrapped in the assembly. Interestingly, the reaction rate of
enzyme in the core of the assembly was twice as fast with free enzyme. By
determining the kinetic constants of enzymatic reaction, it was confirmedthat the enhanced effect of enzymatic reaction was induced by the effective
condensation of the substrate to shell-layer of the assembly. Hence, theshell-layer might work as a reservoir for the substrate. This suggests thepossibility of further encouraging the enzyme reaction without chemicallyconjugation of the enzyme with polymers, by increasing the affinity of thesubstrate and the shell-forming segment.

Enzyme-entrapping core
Shell : PEG

Several tens
nanometers

Fig.1 Chemical nano-machine entrapping enzyme in the core

2. Environmental-Responsive Chemical Nano-machines
We confirmed that core-shell type multimolecular assembly
entrapping enzyme in the core, as shown in Fig.1, exhibited a reversible
formation with the change in the ionic strength (NaCl concentration) in
the aqueous solution. Enzyme was entrapped in the core at a low ionicstrength, but was released from the assembly when the ionic strength wasincreased. The enzyme once again returned to the core of the assembly
after the ionic strength was lowered. It was applied this behavior as onoff control system of enzymatic reaction. In order to evaluate enzyme
activity, a substrate (bacterial cell) with larger size than the assembly wasused. There observed no activity, when the enzyme was entrapped in theassembly (low ionic strength), since the enzyme could not interact withthe bacterial cells. However, increasing the ionic strength, the enzyme
was released from the assembly and could easily interact with thesubstrate, at which enzyme activity was shown (see Fig.2). It was also
confirmed that this process was repeatable, and enzymativactivity could
controlled through the reversible formation of core-shell type assembly.
3. Chemical Nano-machine System Using the Core of Assembly
as Enzymatic Nanoreactor
As mentioned above, the enzymatic reaction is controlled through thereversible formation of the assembly. Such assembly has another possibility
as applied material by using the core of the assembly having the structure
shown in Fig.1 as an enzymatic reaction field. Thus, it was evaluated the
enzyme activity of lysozyme in the core of the assembly. In this evaluation,
the substrate with relatively small size, which could diffuse into the core of

Release amount of
p-nitrophenol (10-6 mol)

5.0
4.0

Enzyme in the core

3.0
Enzyme

2.0
1.0
0.0

0

50

100
150
Time (sec)

200

250

Fig.3 Release profile of p-nitrophenol with enzymatic reaction
using the core of the assembly as a reaction field

4. Conclusion
Using self-organization between an enzyme and a synthetic polymer, we
prepared multimolecular assembly with an average particle size of 50 nm
having a core-shell structure for entrapping the enzyme. The formation of theassembly exhibited a reversible behavior that could be controlled by external
stimuli (modifying the ionic strength). It was confirmed that such external
stimuli can be used to turn the enzyme activity on and off. We also confirmedthat the core of the assembly could be used as a nanoscopic enzymatic
reaction field. Based on such interesting behavior, the assembly could be
aptly named a "chemical nano-machine." This system shows great promise
not only in enzyme targeting, but in various fields as a diagnostic tool.

8

Study on Biomedical Micromachine Using
Biodegradable Supramolecular- Assembly
Tooru Ooya
Research Assistant Professor,
School of Materials Science, Japan Advanced Institute of Science and Technology
1. Introduction
Recently there has been a general trend of growing expectations throughout theworld in the fields of nanoscale science and nanotechnology. Strategic approaches
are important in the design of biomedical micromachines for controlling molecularforms from nano to micro level. This study focuses on the supramolecular structure
and cylindrical shape of polyrotaxanes, in which numerous alpha cyclodextrins (aCDs) are threaded onto a polyethylene glycol (PEG), to investigate the effects of aparticular polyrotaxane structure on the function of molecular recognition.
2. Enhanced Enzymatic Recognition by Supramolecular
Structure of Polyrotaxanes
In synthesizing the polyrotaxane, a peptide sequencephenlyalanylglycylglycine (FGG) is introduced at the ends of thepolyrotaxane as the oligopeptide group. FGG itself can be completelydegraded by an exo-peptidose, such as aminopeptidase M (AP-M). From
the result of in vitro experiment, it was found that FGG in FGGterminated PEG that had not been threaded through the a-CD cavity
degraded only 30%. This indicates that increased while molecular weight
due to conjugation of FGG and PEG are chemically bonded andinteraction between the AP-M and FGG terminals. On the other hand,degradation of FGG-terminated polyrotaxane completely proceeded,
indicating that the interaction increases again due to a-CD threading
through the PEG (see Fig.1). Since the Km value was about 1/22 of the
FGG-terminated PEG, it was suggested that the supramolecular structureof the polyrotaxane actually improved the enzymatic recognition.

Polyrotaxane

BiotinStreptavidin

Vibro-Stirrer

Cuvette Body

Immobiiized sample layer
Gold film

Prism

Laser

Detector

Fig.2 Image of polyvalent interaction between a polyrotaxanebiotin conjugate and streptavidin in a surface plasmon
resonance (IAsys, Affinity Sensors)and Dr Ikumi Tamai of Kanazawa University, Department ofPharmaceutical Sciences. A dispeptide of varyl-lysine (Val-Lys) that istransportable via peptide transporter (PepT1) was introduced into
numerous hydroxyl groups of polyrotaxane. PepT1 is well known to be
expressed in the small intestine on the brush border membrane ofintestinal epithelial cells. In the in vitro experiment, we studied thecapacity of the polyrotaxane cylindrical structure of the synthesized ValLys-polyrotaxane conjugates to inhibit transporting (uptake) of a
dipeptide derivative (glycylsarosine; GlySar), which is specificallyrecognized by the PepT1. It was confirmed that the conjugate included
about 46 molecules of Val-Lys in one molecule of polyrotaxane. The
uptake of GlySar was decreased by adding this conjugate to a Hela cell
culture medium in which PepT1 was stably expressed. When convertingthe concentration of Val-Lys to the same concentration of Val-Lysintroduced dextran or Val-Lys-introduced a-CD, the inhibition is weaker
than when using Val-Lys-introduced polyrotaxane. This suggests thatthe cylindrical structure of the polyrotaxane is effective in theinteraction between Val-Lys and PepT1. Therefore, it is suggested that
Val-Lys in the conjugate polyvalently interacts with PepT1 (see Fig.3).

Threading of a-CD(%)
033.5±2.5
025
50
75 100Cleavage of Phe-Gly bond(%)

Fig.1 The effects of a-CD threading on the terminal tripetide
degradation by aminopeptidose M

3. Recognition of polyrotaxane-Biotin Conjugates
Approximately 300-400 hydroxyl groups exist along the cylindrical structure
in one molecule of polyrotaxane. If numerous water-soluble ligands are
introduced, it is expected that the ligands become oriented along the cylindricalstructure of the polyrotaxane. Based on the hypothesis biotin was introduced
into the polyrotaxane and its interaction with streptavidin (SA) precoated on thesurface of a sensor was analyzed using a surface plasmon resonance (SPR)
appratus. From the SA binding curve during the coating process, the surface
density of the SA was estimated at 2.5 ◊ 10-5 nmol/mm2. Based on a theoreticallength estimated on the presumption that the polyrotaxane-biotin conjugate iscylindrically shaped, a polyvalent interaction such as that shown in Fig.2 isconsiderable. The biotin introduced into the polyrotaxane was recognized by SA
which was confirmed from the binding curve when adding the solution containing
the polyrotaxane-biotin conjugate. This demonstrates that molecular designs
introducing ligands in cylindrical structures of polyrotaxane can be used asprobes for recognizing specific receptors.
4. Inhibiting Peptide Transporter (PepT1) function by
Dipetide-Polyrotaxane conjugatesThis work was carried out collaboration with Professors Akira Tsuji

Dipeptide
O OH

O

OH

O OH

O

OH

O

H
H
N
N
+
-OOC
O NH3
O Varyl-lysine(VK)

HO

Lumen
O

O OH

O

pH5.5~6.8

PepT1

H+
Intestinal EpitheliumFig.3 Illustration of Inhibiting transport of dipeptide is inhibitedby polyvalent interaction between a polyrotaxane-VK
conjugate and PepT1

5. Conclusion
The above results indicate that the supramolecular structure andcylindrical shape of the polyrotaxane is useful for (1) forming an
enzyme-substrate complex and (2) controlling receptor recognition.

9

Micromachine System for Micro-optical
Smart Pixel Application
Hiroshi Toshiyoshi, Lecturer,
Hiroyuki Fujita, Professor,
3rd Division, Institute of Industrial Science, The University of Tokyo
1. Introduction
We designed and manufactured two-dimensional micro-mechanicaloptical scanners and evaluated their properties with the aim of applying
smart pixels in optical communication switching. Smart pixels are used
to integrate mechanical, electrical, and optical devices in a micro threedimensional space.
2. Micro-mechanical Smart Pixels
Fig.1 shows a conceptual view of a micromachine system, the objectiveof the present study, employing smart pixels to integrate micro-mechanical(MEMS) elements. This system includes an array of optical input fibers andoptical beam steering elements (scanners) using micromachines. The
optical switching function is achieved by projecting an optical beam onto
corresponding output ports. As shown in the diagram, a lens, diffraction
grating for wavelength selection, and filter are inserted between the input
and output fibers to magnify the beam scanning angle.
MEMS beam steering device

MEMS beam steering device

Input port fibers

Output port fibers

Max Distortion 0.33%

Position Y mm

1
100%
0

F

S
M

-1
-1

0
Position X mm

1

Fig.3 Results of scanning with the mirror scannerconstruction, it was possible to prevent beam aberration and to shorten
the switching time. The construction can also contribute to lowering
signal leakage if the switching paths are arranged skillfully.
4. Micro-lens Two-Dimensional Laser Scanner
Fig.4 shows an optical transmission scanner employing the XY
movement of a micro lens. Unlike the mirror type scanner, the lensmovement and scanning angle of the light are linear. Further, the lenscan be maintained at a desirable position. Four polysilicon scratch drive
actuators are employed to drive the lens. The lens position (scanning
angle) is controlled through the counting of voltage pulses.

Lens, diffraction grating, filter

Fig.1 Concept of micro-mechanical smart pixels

3. Two-Dimensional Torsion Mirror Laser Scanner with
Electrostatic Actuators
Fig.2 shows an electrostatic torsion mirror device serving as a twodimensional optical scanner, using a micro mirror to reflect light. The
transter function of this device has large nonlinearity and crosstalk.
Hence, complex feedback control would be needed to achieve precise
positioning control in a device for modifying the optical path of smart
pixels, for example. In order to simplify transient control for switching,
we developed a reliable open-loop control method and an analyticalmodel. The drive voltages are determined based on this model. Fig.3
shows the reflected beams projected on a grid pattern grating. With thisOuter Frame

Torsin Bar (f-scan)

Y

V1

V2

100~200 V, 30~340 Hz

5. Conclusion
As described above, we developed two types of trial opticalscanners: a reflection type and transmission type, evaluated theirperformances, and built an analytical model. We were able to gather
much data on process yields inherent in surface machined devices,
failure modes during operations, and analytical methods. We would liketo further reduce the size of these devices and attempt to integrate themwith an actual control drive circuit.

fXu
Mirrorf

Torsin Bar (u-scan)

400µm

V3

Pulse CounterFig.4 Two-Dimensional micro-lens laser scanner

Zu

Inner Frame

500µm

Lock Mechanism
V4

Acknowledgments
The results of this study were obtained through joint research
conducted during FY 1999 and 2000 in the laboratory of Prof. Ming C.
Wu of UCLA's Electrical Engineering Department.

Scratch Drive Actuators

Fig.2 Two-dimensional torsion mirror laser scanner10Experimental Study on Fluid Flow and Heat Transfer inside
Microchannels Utilizing Micromachining Technology
Shigefumi Nishio, Professor,
Kiyoshi Takano, Research Associate,
2nd Division, Institute of Industrial Science, The University of Tokyo
1. Introduction
As channels are being manufactured with increasingly smaller innerdiameters, we are beginning to see the emergence of a peculiar
thermohydrodynamic effect. This suggests that estimations on thenormal scale can produce major errors, making it impossible to estimate
the flow and heat transfer characteristics of a fluid with precision. The
present study is aimed at determining the channel diameters at which
specific thermal and flow phenomena occur and clarifying thecharacteristics of such phenomena. In general, heat transfer increases
with decreases in the equivalent diameter. However, we hypothesizedthat heat transfer may reach a maximum value at a certain diameter. It
is conceivable that the results of this study will provide valuable
information for many fields with broad applications.
2. Experiment Methods and Equipment
Fig.1 shows an overall view of the equipment used in the experiment.
The equipment comprises a (1) fluid supply system (micro-pump, buffertank, filter, pressure gauge of diaphragm type, and flowmeter), a (2) fluid
heating and vacuum insulation system (constant temperature bath andvacuum pump), and a (3) cooling-fluid supply system (constanttemperature bath, pump or air blower, and magnetic flowmeter).

u

r
i

r
y

r
t
e

q Test Liquid Inlet
w Hot Water Circulatione Vacuum Chamberr K-Type Thermocoupleqew

t Cooling Chambery Micro-channelu Window
i Test Liquid Outlet

Fig.2 Detailed construction of the test section

The Nusselt number Nu i in the present experiment was within a range ofabout 0.7-1.0. This value is clearly smaller than the fixed value 4.36 forlaminar flow at a constant heat flux on the normal scale and is 1.7-3 times
higher than the results of Choi, et al. Further, the Nusselt number Nui wasclearly shown to be dependent on the Reynolds number Re, as the Nusselt
number Nui decreased along with decreases in the Reynolds number.
4. Conclusion
The following conclusions were made after analyzing measurementsof the coefficient of friction and the average Nusselt number Nu i in a
microchannel having an inner diameter of 52.9µm and a length of 30mm.
(1) The average Nusselt number exhibited heat transfer characteristics
thought to be inherent in microchannels, including a value lower than
the normal scale and decreases dependent on the Reynolds number.
(2) From the above results, a diameter near the lower limit that exhibits
heat transfer characteristics on the normal scale is optimal for thedesign of heat exchange devices. However, this issue needs to be
examined further in the future.

Fig.1 Overview of equipment used in the experimentFig.2 shows a detailed construction of the test section in theexperimental equipment. Since the test section should be designed to
drastically reduce heat loss around the microchannel, all parts except thefluid heating unit at the inlet are made of an acrylic resin. Fluid is
introduced through the test liquid inlet (1), where it is heated to aprescribed temperature (50˚C) by circulated hot water (2).
Subsequently, the fluid passes through a vacuum chamber (3) and isintroduced into the microchannel (6). During the experiment,
measurements are taken of the fluid temperature at the inlet and outlet ofthe microchannel, flow rate of the fluid, temperature and flow rate of thecooling water, and pressure of the fluid at the inlet to the microchannel.
3. Results
As for the friction factor on the normal scale, f, the f-Re value is fixed at
64. In the present experiment, however, the f-Re value was approximately
twice that on the normal scale. While this is considerably higher thanresults of microchannel measurements reported thus far, the reason for thishigh value has not been identified at this stage. Fig.3 shows themeasurements taken of the average Nusselt number Nu i in the channel.

Fig.3 Measurements of the average Nusselt number

11Low Noise Feedback Interferometryfor Micromachine Servo Actuators
T.H.Barnes
Professor,
Physics Department, University of Auckland, New Zealand
1. Introduction
In this project we have developed the new technique of feedback
interferometry for micro machine applications where displacement
measurements to an accuracy of a few nm are desirable. Feedback
interferometry has the potential to measure phase rapidly, with highaccuracy, using simple optical systems, but its performance limits havenot been know until now.
We have for the first time determined feedback interferometer
accuracy, the conditions under which they are stable, and their noise
performance. We tested our theory in the laboratory using a prototype
high-precision feedback interferometer. It was capable of measuring
movements with a repeatability of l/80, and linearity better than l/100.
2. Principles
Fig.1 shows a generic feedback interferometer. The output intensityof the interferometer is used to control the phase in one arm of a two
beam interferometer. The instrument measures the interferometer
phase fi which in a micromachine system might - for example - arise
from movement of the other interferometer mirror. By solving the
feedback interferometer equation:
I o/ B=1+cos ( f i +GI o/ B) .............(1)we find that the interferometer output intensity Io varies linearlywith phase. Interferometer phase can then be determined directly fromthe output intensity (Fig.2). The system can track accurately over
several wavelengths.

3. Experiments and Results
Fig.3 shows our prototype interferometer to compare the accuracyof feedback interferometry with conventional phase-stepping andheterodyne techniques.
Feedback is applied via mirror M2, with mirror M1 moved by piezo
actuator to vary interferometer phase.
Fig.4 shows the interferometer accuracy. The phase from feedback
interferometery is linearly related to that phase stepping withrepeatability of l/80.

Fig.3 Experimental Interferometer System

Fig.1 Feedback InterferometerFig.4 Phase Measurement Characteristic

4. Conclusion
We have shown that feedback interferometry is a promising
candidate for application to micromachines. It is capable of highaccuracy and linearity with a simple opto-electronic system that can bemade to operate at high speed.

Fig.2 Feedback Fringe Profile

12

Members' Profiles

Toshiba
Corporation
1. Achievements of Micromachine Technology
Under the Industrial Science and Technology Frontier Program,Toshiba, along with Denso and Sanyo Electric, has developed an"Experimental Wireless Micromachine for Inspection on Inner Surface
of Tubes" for applications in confined areas like the narrow piping inelectric power plants. This "microrobot" can move along a pipe having a
diameter of 10 mm, while transmitting images ahead and debris inside
the pipe. The microrobot is driven by energies received wirelessly fromexternal microwave and laser sources.
In this project, Toshiba was in charge of developing a "CCD
Microvision System" to be mounted on the front of the microrobot. The
microvision system comprises a color video camera with built-in
focusing mechanism mounted on a 2-DOF universal head, all powereddriven, in the body-size of 25 mm in length and 8.9 mm in diameter. In
developing this system, we achieved various advances in camera size
and image quality that have not been paralleled under such restrictedenergy conditions and transmission capacity.
We also developed various element technologies necessary todevelop this microvision system, including micromachining, highdensity three-dimensional packaging, electrostatic micromotor, and thincatadioptric system technologies. We further developed assembly
technology for integrating the above components and a method forconstructing images to support the small transmission capacity, alongwith technical development on systematization.
25mm

Nobuyuki Toyoda
Deputy Director
Corporate Research & Development Center

3D Endoscope

Stereoscopic Micro Vision
CCD

LSI
Electrostatic Actuators

Fig.2

micro-sized CCD unit and electrostatic linear motor mounted in the
microvision system, it is possible to construct a stereoscopic camerathat can fine-tune the three-dimensional effect and should contribute
greatly to examinations and surgery.
We also developed new systems applying some of the element
technologies that were developed in the microvision system for the trial
production and verification of practical devices. In Fig. 3, theelectromagnetic micromotor has been applied to an in-pipe inspection
robot with wheels. An electromagnetic motor having a diameter of 5
mm is mounted on a 7-mm diameter case for a 400,000-pixel CCD.
Observing the inner pipe walls are performed using a focusing
mechanism formed of a shape-memory alloy (SMA). The robot canobserve debris as small as 20µm in a pipe with a minimum diameter of
20 mm. Powered by wiring, the robot can be used in environments inwhich microwaves or lasers cannot.

f 8.9mm

Separable Body Type Polymer Body TypeElectrostatic Wobble Motor,
f 2.5mm, f 6.5mm,

3D Packaged LSI Module,
4.435.2311.5mm
CCD, 1.6mmu, 100Kpixels

Catadioptric Lens,f 2.5mm31mm

Electrostatic Linear
Motor, 4mmu38mm

Fig.1

2. Future Activities
In addition to mounting the microvision system on the in-pipe
inspection microrobot, we hope to apply this system to new applications
using the entire system or individual element technologies. The first
applications that come to mind are in the security and medical fields. In
terms of the former, the development of information network services ashousehold and social infrastructures is likely to make wireless imagetransfers from remote locations possible in the near future. The
microvision system is expected to have few restrictions in the number
and location of installation because of its ability to freely change viewing
angles and the fact that it has 1/1000 the volume of conventional devices.
In the medical field, it is likely that the microvision system can beapplied to examination apparatus used in laparoscopic and endoscopic
surgery, which are now receiving much attention as minimally invasive
operating methods that allow quick recovery period. By combining theHigh-output motor and planetary wheel mechanism

CCD camera (7 mm in diameter)

Electrostatic motor
SMA focusing mechanism

Fig.3

3. Future Stances
Other conceivable applications for the microvision system include
PDAs and robot eyes. We plan to continue these studies as deemed
appropriate for satisfying the needs of society.

13

Hitachi, Ltd.
1. The Challenge of Micromachine Technology
Hitachi Ltd. manufactures a comprehensive array ofelectrical machinery and appliances, such as nanometersized electronic devices, consumer products, power andenergy systems, and industrial machinery. We supply
products and services in a wide range of fields and are
implementing projects on a global level.
Micromachine technology is a cutting-edge basic
technology that will shape the 21 s t century. The
Mechanical Engineering Research Laboratory is chiefly
responsible for R&D on micromachines at Hitachi Ltd..
The entire research laboratory is working together on
this research and development with the aim ofincorporating our basic technologies in mechanicalsystems as a base to provide the best customer solutions
in such fields as medical and human-care, theenvironment, information, and communications.
2. Development of Micromachine Technology
Hitachi, Ltd. participated in the planning for"Micromachine Technology," part of the Industrial
Science and Technology Frontier (ISTF) Program
sponsored by the Ministry of Economy, Trade, andIndustry that was completed in March 2000, and oversaw
research and development on element technologies andsystem integration technology for developing a
microfactory, the concept of which is a micro-sized
system for producing small numbers of many products.
The anistropic wet etching process for single-crystal
silicon, which Hitachi, Ltd. has developed over many
years, is gradually having a rippling effect on the creationof micromachines, which will benefit society.
2.1Achievements of the Industrial Science andTechnology Frontier Program
In overseeing the research and development on a
microfluid operation technology, we developed amicrofluid operation device for supplying corrosive
working fluid for micromachining and a holding device
End ofmicroarm

Hiroshi Ohki
General Manager
Mechanical Engineering Research Laboratory

for assembling microparts. By incorporating surface
treatment and forming techniques on a micrometerorder, we developed a microfluid sealing method forrotary driven trochoid and scroll pumps. In this way, weachieved a micro size while maintaining high output.
These features were applied to a fluid pump for
supplying fluid and a vacuum pump for holding
microparts. Both devices were then incorporated into a
trial microfactory system to verify the processing andassembly operations of a microgear. Fig.1 shows aholding device (vacuum chuck; outer diameter of 7mm
and length of 26mm) mounted on the end of a microarm(manipulator) used in assembly operations. The holding
device conveys a microgear having a diameter of 2.6 mm.
2.2Achievements in Silicon Micromachining
Technology
We applied silicon micromachining technology to thedevelopment of a small sized water quality monitor thesize of an A4 sheet of paper (1/100 the conventional
volume). This device contributes to human safety andhealth management by automatically measuring residual
chlorine and the like in water pipes for generalhouseholds that have extremely limited installation
space. The primary feature of this device is that it
employs microfluid channels produced by siliconanisotropic wet etching (see Fig.2).

Pad

Absorbing cell
10mm

Motor
Microgear

Mixer

Fig.2 Microfluid circuit for a small sized water quality monitor

Pump

3. Future Stances
In our future challenges, we would like to apply theachievements of the Industrial Science and Technology
Frontier Program to the field of micro total analysis
systems (µTAS) to develop an analyzer for medical andenvironmental applications.

Conveying pallet
5mm

Pad

External view of
vacuum chuck

Water inlet

1mm

Microgear chucked by
the holding device

Fig.1 Vacuum chuck and operation of chucking microgear

14

Introductory Course

Medical Applications for Micromachines Part 2
Iwao Fujimasa,
Professor,
National Graduate Institute for Policy Studies
carried out with its aim set squarely on the nano world; furthermore, bioindustry has begun creating a huge industrial base for the twenty-first century.
Naturally, medical technologies have also started to directly handle items suchas tissue and cells, and deserving of particular attention is the commencementof studies within the field of genetic medicine focused on intracell injection
methods for substances with dimensions between several microns and severalhundred nanometers. These studies have been started due to the meaningful
medical treatments for a wide range of sicknesses which will be possible if
remote operations can be used to inject a specific DNA probe into a target cell.

From Macro to Micro
From the beginning of the development of micromachine technologies-now
proceeding for over ten years-it has been considered that the field of medicalcare held the potential for the most important, and furthermore, most basic
demands. This time also saw the start of the transfer of practical technologies
from the macro world to the micro world-or in other words, to the submicroscopic world-with the field of medical care being represented in the formof micro surgery. The principal reason for this lay in the fact that medical care
had become focused on treatment; furthermore, this in turn resulted from thedimensional change which occurred in the field of medical care over the pastten-odd years: Specifically, treatment began to move away from classical,
macro applications such as the removal of unneeded organs or, for example, theinjection of medicines over the entire body, and it started to develop in a world
where cells, tissue, or even organs which were less than a centimeter in size oreven smaller became the primary subjects for application. Cells are the primaryelements of life; accordingly, a realization developed that as the subject for
application of medical technologies became smaller and smaller, it would
become possible to conduct medical activities which would be more significant
in terms of human life. In addition, it also became possible for several medical
technologies from the micro world to be put to developmental use.
In the case, for example, of surgical practices-as represented by micro
surgery-over fifty percent of all related fields now involve actions requiring aloupe or microscope; furthermore, micro-forceps and micro-scalpels have now
been applied to use for these tasks. Even in the case of the endoscope
operations which have revolutionized the world of surgery over the last ten
years, these have become characterized by micro-remote operations carriedout via a trocar of less than one centimeter in diameter. Originating frommanual industrial methods, these operations have begun to change in afundamental way through the incorporation of rapidly-developing video-data
technologies and also through the implementation of technologies from theworld of artificial-reality sensing. Already, a large portion of the scalpels,
syringes, and micro catheters which are used for the purpose of actual in-bodyoperations in the microscopic realm are provided as one-application,
throwaway devices, and for this reason, the majority of the associatedtechnologies now require mass-production processes which employ industrial
technologies. It may be said, therefore, that the world of micromachinetechnologies has now for the first time developed a need for industrial
operations.

The Arrival of Nano Quantum Systems
Suitable handling technologies will be required in order that
substances and items of nano-dimensions may be directly operated
on, and the majority of these correspond to micromachinetechnologies. In this world, however, problems lie hidden in thenano region-the region where micromachines now reside. The DNAbase pairs as used by biochips are of several nanometers indimension, and on-chip labs handle material volumes which are lessthan a nanomole (i.e., 10-9) in concentration. As indicated recently
by many researchers, the reduction of dimensions whichaccompanies the shift toward micromachine technologies has,when considered from the point of view of material units, reached
the realm of several molecules, and further reduction to thequantum level cannot be avoided. The materials which are
subjected to direct operation in the majority of medical-chemistry
examinations have material volumes of the nanomole level. Since asolution containing 631023 molecules per liter is said to have aconcentration of one mole, one cubic millimeter of a one nanomole
solution will contain 63105 molecules. Accordingly, in the world of
nanomole examinations where elements of ten microns in size areused, an examination chamber containing one nanomole of solution
will actually hold a 1/106 fraction of this number-in other words, 0.6
molecules. Micro-TAS (total analysis system) and other similar
technologies recently under development have incorporated thisdynamic, open-system world; accordingly, this indicates entry into
the realm of quantum-wave mechanics, where physical laws
become uncertain with regard to classical and deterministic
theories.
Meanwhile, in the case of micromachining technologies where
the one-micron barrier has already been broken, the size of theexamination elements which this creates has dropped to a levelmeasured in cubic-micron units. In micromachines which havebeen manufactured with dimensions close to one micron, themajority of macro-world rules will not be applicable with respect toinduction of the chemical reactions which handle the substances
contained. Analysis in the micromole range has recently become
the most commonly-applied, and with the exception of those cases
which handle protein structures and other substances of a certain
degree of size, it may be said that for this type of analysis also, asolution must be found for the electronic-related uncertainty
problems in systems which perform analysis using commonlyapplied electrochemical electronic reactions. If nanomoles are to
become the subject of operations, this world will expand to include
technology where today's regularly-produced micromachines havesides of one-hundred microns, and it is quite possible that newtechnologies will be required for examination and materialidentification purposes. In other words, if the world of microelectromechanical systems were to coincide with the world oforganisms containing aqueous solutions, this would lead to the startof the creation of, not a micro world, but a nano world;
furthermore, it should be emphasized that biomedical
micromachines have already entered the realm of the nanomachine, and that further reduction to the level of nano-quantum
systems is an inevitability.

From Micro to Nano
Occurring almost simultaneous with the start of transition from macro to
micro for those items subjected to medical-treatment practices, the subjects of
examinations also began to switch from microscopic cells and metabolites of acertain density towards cell-internal organelles, genes, and minute volumes of
immune-system substances; similarly, such examinations have also begun todeal with items and substances which are more important with regard to life
control. Since the dimensions of cell-internal substances now correspond to
the nano level, and because it is now necessary to handle extremely low
densities measured in nanomoles, it may be said that a shift from micro tonano is beginning to occur for examination items. We cannot allow ourselves
to ignore the passage over the past ten-odd years-as characterized by thehuman genome project and the like-of the science of biomedicine into therealm of the nanometer.
Although the development of biomedical examination elements anddevices has been overlooked during the course of previous micromachine
projects, it may be taken for granted that bio-elements, chips, and the like will
be incorporated into the next generation of micromachine and nanomachinetechnologies. Furthermore, the last few years have seen rapid development
both in the field of industrially-manufactured DNA chips, protein
immunochips, and the like, and also in the field of micro-inspection elements
as typified by on-chip labs which are put to bed-side use as liquid inspection
chips; these developments, too, may be considered as a natural matter ofcourse. As indicated by the announcement of the DNA chip in 1997, thedevelopment of post-genome technologies in the field of biomedicine is being

15

TOPICSThe 7th Micromachine Summit
The 7th International Micromachine Summit was held for three days from April 30 to
May 2,2001, in Freiburg, the cultural and economic hub of southern Germany.
The Summit was attended by 72 delegates representing a total of 20 countries andregions. The Japanese delegation consisted of four presenters and five observers.
Based on the principle, "ideas are transferred by the people" the summit gave
participants a opportunity to present new information to others, to use in further researchor to develop applications in industry. The Summit was jointly chaired by two leading
professors from Albert-Ludwig University in Freiburg : Prof. Wolfgang Menz (also directorof the IMTEK Research Institute) and Prof. Jan G. Korvink.
The central topic of the 7 th International Micromachine Summit was MEMS
education. The MEMS education programs in some countries are designed to boost
numbers of engineers and technicians based on the needs of the marketplace, as
exemplified by BASIC (Biology, Automation, Semiconductors, IT, and Communications).
The MEMS education program in Japan, was introduced in a presentation on how theMicromachine Center is helping to have a dream and interest held in young children's
mind for science and technology through an "annual Micromachine Drawing Contest" anddistribution of educational videos on micromachines. The presentation has had

considerable success from the viewpoint of showing charm points of science andtechnology and drawing eyes of young people through the smallest robots,
micromachines. The 8th International Micromachine Summit will be held in April next year
in Maastricht, Netherlands.

THE SEVENTH INTERNATIONAL MICROMACHINE SYMPOSIUM
1. Date : Oct.31 and Nov.1, 2001
Oct.31 (09:30-17:40, reception 18:00-20:00)
Nov.1 (09:30)
2. Venue : Science Museum, 2-1 Kitanomaru-Koen, Chiyodaku, Tokyo
3. Admission fee : ¥15,000 (including proceedings, reception )4. Acceptance window : Micromachine Center International Exchange
Dept.
Tel :03-5294-7131 (+81-3-5294-7131),
Fax:03-5294-7137 (+81-3-5294-7137)
5. Acceptance closing : Oct. 19th (Fri),2001❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉ PROGRAM (Tentative) ❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉❉
October 31, 2001
9:00 -Registration
Session 1 : Opening
Chairman : Mr. T. HIRANO
9:30 -- 9:35
Opening Remarks
Mr. Toshiro SHIMOYAMA, Chairman, Micromachine Center
9:35 -- 9:42
Guest Speech
Mr. Iwao OKAMOTO, Director-General, Manufacturing Industries Bureau, METI
9:42 -- 9:50
Guest Speech
Mr. Tsutomu MAKINO, Executive Director, NEDO
9:50 -- 10:30
Special Guest Speech: Micromachine Based Business Model (Tentative)
Prof. Fumio KODAMA, Tokyo University
Session 2 : The Path to Micromachine Industries in the 21st Century
Chairman : Dr. S. HIRAI
10:30 -- 10:50
R&D Strategy for Micromachine Technology
Prof. Isao SHIMOYAMA, Tokyo University
10:50 -- 11:10
Manufacturing Outlook (Tentative)
Prof. Susumu SUGIYAMA, Ritsumeikan University
11:10 -- 11:30
Application for IT (Tentative)
Dr. Hironobu KUWANO, NTT Cyber Solution Laboratories
11:30 -- 11:50
Medical Application (Tentative)
Prof. Mitsuo OKANO, Tokyo Women's Medical College
11:50 -- 12:10
Integrated Chemistry -- State-of-the -Art and Scenario Toward Industrilal Innovation
Prof. Takehiko KITAMORI, Tokyo University
12:10 -- 13:10❋❋❋❋❋❋❋❋ Lunch ❋❋❋❋❋❋❋❋
Session 3 : Activity in Overseas
Chairman : Mr. R. MAEDA
13:10 -- 13:40
Status of Five Clusters in EU (Tentative)
Mr. Rob TURNER, Operating Manager,NEXUS
13:40 -- 14:10
Radio Frequency Identification
Prof. Heikki SEPPA, Finland, VTT
14:10 -- 14:40
MEMS Research EnvironmentProf. Yitshak ZOHAR, Hong Kong University of Science and Technology
14:40 -- 15:00❋❋❋❋❋❋❋❋ Break ❋❋❋❋❋❋❋❋
Session 4 : Innovative R&D
Chairman : Prof. H. FUJITA
15:00 -- 15:20
Light Driven Mass Migration in Nano-Hybrid Polymer Films
Prof. Takahiro SEKI, Tokyo Institute of Technology
15:20 -- 15:40
Development of Visual Prosthesis
Dr. Toru YAGI, Nagoya University
15:40 -- 16:00
Nano-photonics and Micromachine/MEMS
Prof. Satoshi KAWATA, Osaka University
Session 5 : Micromachine in Past Decade and Future Outlook
Chairman : Prof. I. SHIMOYAMA
16:00 -- 16:20
Contribution of Micromachine Center(Tentative)
Prof. Hirofumi MIURA, Kogakuin University
16:20 -- 16:50
MEMS Development in the Last Decade
Associate Prof. Norman C. TIEN, University of California
16:50 -- 17:10
Practical Use of Micromachine in Industry (Tentative)
Dr. Kunihiko HARA, DENSO Corporation
17:10 -- 17:30
Micromachine Research in Universities in the Last DecadeProf. Hiroyuki FUJITA, Tokyo University
18:00 -- 20:00
Reception Party at KKR Hotel Tokyo

November 1, 2001
Session 6 : Results of Micromachine Technology Project in ISTF Program
Session 7 : Closing

Pictures on the cover : Winning artworks in the Micromachine Drawing Contest
Micro-Pupfish, Mr.Ripe-Fruit, Schedule Diary for the Future, Micromachines Bring Hope (from top to bottom)

MICROMACHINE No. 36
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 ofchange. 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
Internet Home Page h t t p : / / w w w . i i j n e t . o r . j p / M M C /Change of Address : Please send old address lebel and new address to the publisher.
Editorial and Production Management : Japan Technical Information Service (JATIS)
Date of Issue : August 17, 2001

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