• View on Year 2001
• AATC of SRI International• 6th Internat. Micromachine Symposium• The Special Lecture• Micromachine 2000 Held
• Rep. on Appl. of Other Field New Technology• Member's Profiles•••

Seiko Instruments Inc. /TERUMO CORPORATION
Foreign View / IWMF2000
TopicsMicromachine Asia Seminar /2000 Micromachine Asia Mission
Latest Micromachining Technology (IV)1

View on Year 2001 at the
Beginning of the Year
Iwao Okamoto
Director-General, Manufacturing Industries Bureau,
Ministry of Economy, Trade and Industry

I wish to offer my wholehearted New Year’s greeting to eachand everyone of you at the beginning of the 21st century.
The economy of Japan has still not extricated itself from adifficult situation due to the delay in improving on its financial and consumption sectors but a continuous movement towards autonomous recovery centering on corporations does exit
and, overall, the tendency is a slow but steady improvement in
the right direction. To ensure that the economy is on the righttrack to self-recovery, the government is resolved to continue
reforming the structure of the economy in a form appropriate
to the new century whilst endeavoring to achieve economic
recovery.
I am of the firm belief that the domestic manufacturingindustry will continue to develop energetically in the new century and to support the economy of this country, but also I believe there are many outstanding issues that will need to beaddressed. Many such issues will depend to a large extent on
the endeavors of you in the industrial sector, but the administration will certainly attempt to come to grips with the essential matters which I will refer to hereunder in order to provide
support and promote your efforts in this connection.
I.

Strengthening Competitive Potential/Reorganization of the Business World
Improving the productivity of Japan’s industries andstrengthening their competitive potential are two extremely
vital strategic themes, the realization of which will enable our
economy to secure sustainable growth in the first half of the
21st century as the decline in the number of children and population aging become ever more conspicuous. Again, based on
the philosophy of the “Option and Concentration” of management resources, restructuring is being promoted in individual
enterprises even in the manufacturing industry, entailing affiliations and mergers as developments take place. However,with foreign competitors accelerating cross-border, large-scaleaffiliations and mergers and amidst an environment wherereforms and intensification are taking place in demand circles
worldwide in step with rapid increases in global procurements,
what the manufacturing industry of this country needs is a
drastic strengthening of its ability to compete. Towards suchrealization and to come to the point, improving efficiency on awider scale by way of the consolidation of business and mergers, achieving the optimum scale of production and risk investment to include research and development (R&D), are anticipated. In continuation of the enactment of the Industry Vitality Regeneration Special Law in 1998, the government has
been giving full support to corporate business restructuring
and to the reinforcement of legislation in connection with corroborative splits and taxation. Every effort will continue to bemade to resolve outstanding problems, such as the introduction of a consolidated taxation system, and reform of corporate
pension schemes, etc.
II. Strengthening Industrial Technology Skills
In order for Japan to be able to maintain its economic sta-2

tus in the new century, it is recognized that further improvements to its industrial technology skills are essential and, tobe specific, we plan to focus on tackling the points which I will
now refer to.
In the field of biotechnology, with the announcement of asummary of the entire configuration of human genes in June
2000, we entered a new stage and competition at the international level is intensifying for both R&D and industrialization.
Aiming at swift industrialization, the Japanese governmenthas been promoting a millennium project in cooperation withindustrial, academic and governmental circles since 1999 concerning genome analysis, analysis of the functions of protein,etc. In addition, we plan to appropriate a development budget
for technology to replace existing industrial processing with
bio-processing that has a lower environmental load from 2001
and will strive to expand activities in this field. Furthermore,since 2000, this Ministry, in cooperation with other governmental offices, in the process of improving the environment for R&D
by preparing ethical guidelines has been relative to research
and analysis of genes, etc. Inclusive of such measures, we intend to continually pursue measures to ensure the rapid development of the biotechnology industry.
Material nanotechnology including information technology(IT), biotechnology, etc. will lead to the future development of
the social economy in the extensive industrial sector and isfundamental vanguard technology for technological reform, atechnological field in which Japan has commanded a leadingrole to date. The Japanese government has positioned material technology as one of the most vital sectors along with IT,
bio and environmental technology in its next Scientific Technology Basic Plan and, by concentrating industrial, academic
and governmental efforts, intends to actively push R&D in thisfield.
Furthermore, in addition to the promotion of a Digital
Meister Project targeting developments and improving on thestrength of the manufacturing industry to create things, andto develop high-level processing technology required for nextgeneration semiconductors, we also intend to strive for globalization of standardized parts/ machine systems. In addition, todeal with the rapid approach of an aging society and the evolution of an information driven society, a millennium project for
the elderly and an IT barrier-free project will be pursued inorder to improve on the international competitiveness of a wide
range of products and, simultaneously, improve the environment to contribute towards creating things from the viewpointof citizens.
As regards aeronautics and space industry sectors, in order to promote relevant advanced technologies and in an attempt to take the lead in fuselage development at an earlystage on the initiative of the Japanese government, technological ability in high-tech sectors including engines for supersonic aircraft, composite materials, etc. will be strengthened
with the target being to establish technical standards domestically, which can be applied worldwide. In the industrial sectors, which involve the development of large-scale systems suchas the rocket industry, etc., system design and R&D for hightech integration will be pursued to enable trustworthy, lowcost and short-term development.
III. Environmental Measures
Global environment problems and the global warming issue in particular, are important issues which may exert a major influence on the economic activities of the manufacturingindustry. At the COP6 scheduled to be resumed this year, we
hope to proceed with negotiations so as to enable ratificationof the Kyoto Protocol based on the development of the November 2000 negotiations. We shall also undertake to study thepracticability and nature of highly efficient measures so as tobe able to resolve the global warming issue domestically without imposing undue restrictions on either the economy or the
population.
Again, it is recognized that hastening measures to recycle
houses/building materials, paper, PET (polyethylene terephthalate) bottles, fiber, petroleum gas equipment, etc. is also
important. In particular, regarding the recycling of automobiles and based on the reacquisition of scrapped vehicles, investigations are in progress, including the possible enactmentof legislation, with the aim of improving the standard of recycling and securing appropriate disposal and, a draft of suchfundamental framework system and basic way of thinking including the necessity to come up with a system is scheduled to
be formulated by the end of the current fiscal year.
Concerning measures to protect the ozone layer, together
with the promotion of measures for the smooth and total abolition of hydrochlorofluorocarbons (HCFC), etc., a chlorofluorocarbon (CFC) control strategy of comprehensive measures tocope with CFCs will be finalized by the end of the current fiscal year on the basis of the Montreal Protocol. Furthermore, in
addition to enforcing the collection of Freon from electrical appliances in accordance with the Electrical Appliances Recycle
Law, the Freon contained in air conditioning units installed in
automobiles resulting from vehicle disposal, will be collected
as a link in the recycling of cars, and Freon collection fromdiscarded air conditioning and freezer units used in businessinstallations will be promoted. Again, fiscal 2001 will see theintroduction of a new system to control chemical substances.
Based on the Chemical Substances Control Promotion Law, theMSDS (chemical substances, etc. safety data sheet) system will
be put into effect from January this year, the PRTR (measuresrelative to grasping emission volumes, etc. of specific chemical
substances to the environment) from April this year and, efforts will be made to improve on the voluntary control of chemical substances by businesses. To date the industrial world has
been taking a positive attitude towards environmental conservation measures, but with the recent increase in concerns overenvironmental pollution by chemical substances, it is expectedthat further corporate efforts will be exerted with the enforcement of relevant legislation.
IV. Measures Concerning Regional Industry
Promotion of industries, which support employment andlocal economies, is another vital issue. The situation confronting the textile industry in particular is extremely grave as aresult of the sudden increase in imports from China and othercountries. To cope with such circumstances, efforts will be exerted to revitalize textile producing areas by comprehensively
promoting measures for imports coupled with domestic measures aimed at energizing domestic production centers.
On the other hand, influenced by the changes in the life
styles of the domestic population in recent years, etc., demandfor products turned out by traditional arts and crafts has declined and problems such as securing such successors, etc. havecome to the fore as a result. To overcome such problems andpromote independent development of production areas, a review of existing systems (legislation, etc. relative to promoting
traditional arts and crafts industry) will take place to correspond with changes in the times and the status quo while fulfilling and providing indirect support to various efforts madeat relevant producing areas.
V. Trade Issues
Anti-dumping measures are on the increase in the U.S. andother nations on a whole range of iron and steel products imported from Japan in recent years. To address these problems,
measures such as filing suits, etc. to settle disputes on themeasures that are not consistent with the rules of the WTO
are being implemented in conjunction with concerted efforts toresolve the issue at various levels including multilateral andbilateral consultations. The Japanese government will continue
to powerfully promote such efforts hereafter, strive to maintain and develop a fair and free trade environment concerning
issues involving bilateral or regional issues and the Fair Trade
Agreement (FTA) by taking up matters in multiple stages.
As regards the automobile issue that has arisen between
Japan and the U.S., since the measures drawn up in 1995 aredue to expire consultations have taken place regarding thenature of the relationship between the two countries and how
it should be developed in the years after 2001. In consequence,
the Japanese government made a new proposal at a conference which took place in San Francisco in December 2000 regarding a dialogue between the two countries. Although the
U.S. government did not respond to this proposal, we hope todeal with the matter in a proper manner whilst taking note of
the possibility of reorganization in the automobile industry on
an international scale so as to arrive at a mutually satisfactory conclusion.
VI. Conclusion
As of January 6, 2001, the Ministry of International Tradeand Industry became the Ministry of Economy, Trade and Industry. The former Basic Industries Bureau together with asection of the Machinery and Information Industries Bureau
and Consumer Goods Industries Bureau joined forces to form
the Manufacturing Industries Bureau.
In the past we endeavored to make governmental policies
reflect requirements of various industries as the point of contact between various industries and the administration. The
stance of the Manufacturing Industries Bureau will remain
consistent with this. We intend to expand the point of contact
with industries and continue to energetically promote measures
based on the realities of the manufacturing sector from a muchbroader perspective. All of you in the manufacturing sector are
requested and expected to be aware of the fact that the manufacturing sector is the origin of the economic power of Japan at
a time when pessimistic elements are conspicuous regarding
Japan’s economic prospects and to continue working to cometo grips with technological developments, redistribution of management resources and the furtherance of alliances, etc. in order to maintain and strengthen the power of the manufacturing sector. Again, I would like to request that the consequencesand details of such efforts be made known positively to thepeople of Japan. By doing so and in line with the progress inthe series of reforms, the confidence of the people in the economyof this country is sure to be recovered and I believe we shall beable to share a bright outlook towards economic revival.
Lastly, I wish all of you happiness and further prosperityin the New Year.

3

Laboratory Introduction
Dr. Seiki Chiba
Executive Director,
The Advanced Automation Technology Center of SRI International
1. Introduction of AATC
The Advanced Automation Technology Center(AATC) of SRI International (SRI) focuses on thedesign, development, and transfer to its clients ofadvanced automation technologies. These technologies span a wide range of fields and include intelligent document understanding, 3-D machine vision, sensor placement, telerobotics, field robotics,
and new transducer technologies such as artificial
muscle. In the area of new transducer technologies, AATC works closely with other laboratories
within SRI, sharing a wide range of facilities andequipment within SRI. These laboratories maintain state-of-the-art design, analysis, and fabrication facilities including special and general measurement and test equipment, an environmental
chamber, a model shop, chemistry and spray fabrication facilities, and computer-aided design centers. AATC works closely with SRI’s Physical Electronics Laboratory, which maintains clean rooms
and other microfabrication facilities.
AATC has worked with a wide range of government and commercial clients in the US, Japan, andEurope. As a nonprofit institution, SRI transfers
the technologies developed at AATC to the sponsoring commercial clients, or licenses them tomanufacturing companies in the case of U.S. government-sponsored work.
AATC has worked on a wide range of robotic
and transducer technologies. In the area of robotics, for example, AATC developed a laboratory prototype of a pipeline inspection robot. The pipeline
robot used novel magnetic wheels that enabled it
to travel on the walls and ceilings of 15-cm natural-gas pipes. Other research and development focuses on basic transducers; In addition to work on
artificial muscle, AATC has developed novel levitated devices for applications such as sensors (flowmeters, accelerometers, etc.), micromotors, andclean-room automation. AATC demonstrated what
is believed to be theworld’s first passive self-levitated (no bias
forces) magnetic structure at room temperature.
Another sensor area of interest to AATC is tonom-

4

etry, a technique for measuring blood pressure
unobtrusively and continuously. For a number ofyears AATC has developed tonometry technology,
some of which is currently sold commercially.
2. Artificial Muscles
AATC has been investigating artificial muscles
on the “Artificial Muscles in R&D of MicromachineTechnology, industrial Sciences and Technology
frontier Program” since 1992. The term artificial
muscle, analogous to natural muscle, describes any
actuator material that is substantially scale invariant in performance, where larger actuators canbe considered as a collection of mechanically linked
microactuators. For example, a single electromagnetic voice coil actuator is not an artificial muscle
because it is not scale invariant (it has poor performance on small scales), and it is not a collection of mechanically linked microactuators. By contrast, a piezoelectric material has substantiallyscale-invariant performance, and a large, multilayer piezoelectric actuator consists of a collectionof mechanically linked microactuators.
Our goal for the project is to identify and develop an artificial muscle with performance comparable to that of natural muscle. Such an artificial muscle would have overall performance greatly
exceeding that of existing artificial actuators andcould be used for small robots, inkjet printers, micro light scanners, micropumps, and a wide rangeof other microapplications. The artificial muscle
would be particularly applicable to microdevices,
for which existing actuator technologies are limited; but since it is scale invariant, it could also be
used for a wide range of macro applications including robots, speakes, and motors.
The principle of operation of the electrostrictive
polymers investigated by SRI is shown in Figure
1. Unlike other electrostrictive polymers (EPs),
which work via molecular changes, SRI’s EP materials work via bulk electrostatic forces (Maxwell stress). As shown in Figure 1, a relatively softpolymer is sandwiched between two compliant
electrodes. When a voltage difference is appliedbetween the compliant electrodes, the electrostaticforces squeeze and stretch the polymer, thus providing a mechanism for actuation.

Fig. 1 Principle of Operation of Electrostrictive Polymers (Circular Black Areas in Bottom Photos
are Active Electrode Areas).

Figure 2 shows a comparison between artificial muscle and other high-speed actuator technologies. Note that the performance of artificial
muscle exceeds that of natural muscle.

Fig. 2 Comparison Between High-Speed Actuator
Technologies

Many polymer materials have been tested as
artificial muscle. All insulating polymers show
some response, Silicon and acrylic are dramatically
better than others. Note that the strain of theacrylic elastomer can exceed 200%, and its energy
density is higher than that of any known field-actuated material. The acrylic elastomer is a powerful material, but we note that silicone is faster, due
to higher viscoelastic losses in acrylic. Silicones

have a bandwidth greater than 1 kHz, while acrylic
elastomers are currently limited to below 100 Hz.
Research is now concentrating on ways to achieve
the high strain and energy density performanceof acrylics in operation at the speeds of silicones.
In addition to the polymer, SRI is investigating
various electrode materials. Metals such as gold
are typically too stiff and crack when actuated, but
we have found that by suitable patterning theycan elongate up to 80% while retaining their conductivity. For higher strains, particulate materials such as carbon black and carbon nanotubes ina binder generally work well.
We have developed a variety of ways to fabricate artificial muscle. Spin coating of polymers insolvents works well, and we have demonstrated
muscle as thin as 1 µm. Thinner films reduce theoperating voltage, which tends to be higher forelectrostrictive polymer artificial muscle than it
is for other electrostatically driven technologies.
We have designed and demonstrated a wide
range of artificial muscle actuators. Examples include artificial muscle bimorphs and unimorphs
capable of greater than 270 degrees of bending,
artificial muscle diaphragms that can actuate froma flat to a hemispherical shape, and a range ofsimple linear actuators. Application-level devices,such as micro light scanners and minipumps, havealso been demonstrated to show the wide applicability of the technology.
An interesting area for research and development has been the investigation of the unique actuation properties of artificial muscle and the design of actuators that can best exploit it. For example, uses a high prestrain in the polymer in one
direction, together with a flexure design, to enhance actuation in the low prestrain direction.
3. Summary
Research on artificial muscles at SRI’s AATC
has reached an application phase. Strain, pressure,energy density, and response time performance parameters have increased by factors of 5-30 in thelast 2 years. Technical progress continues in understanding the fundamental design of artificial
muscles at the material, fabrication, and actuator
levels. Thus, the near future of artificial muscle
research at SRI’s AATC will focus on both fundamental and application areas.

5The 6th International
Micromachine Symposium
The 6th International Micromachine Symposium
was held at the Science Museum in Kitanomaru Park,Tokyo, for two days from November 9 to 10, 2000.
On the first day, the opening ceremony of the program started with the speeches of three honored guests,
Mr. Shinichiro Oota, director-general of the Machineryand Information Industries Bureau in the Ministry ofInternational Trade and Industry, Dr. Koji Kajimura,director-general of the Agency of Industrial Science andTechnology, and Mr. Hiroshi Mitsukawa, executive director of NEDO. The total registered participants forthe two-day program numbered 447 (51 of them werefrom overseas).
The first lecture in the symposium on the first day
was “Artificial Heart Research by the Use of Micromachine” by Dr. Shinichi Nitta, professor of the Inst. ofDevelop. Aging and Cancer, who is also vice-presidentof Tohoku University. He introduced the audience tocurrent R&D on artificial organs such as artificial hearts
as well as outlining future expectations and prospects.
This year’s program included a study on health andmicromachines in Session 3 entitled, “Thinking ofMicromachines”. Front-line researchers made presentations on today’s hot topics related to micromachinetechnologies, such as medical practices making use of
information derived from the deciphering of the genome,
telehealth, and robot surgery.
Medical treatment technology has been regarded as
one of the most promising micromachine application
fields. We were impressed by those presentations thatshowed how micromachine technology has possibilities
for medical care in the near future. The content of thespecial guest speech is presented on the following pages
for your reference.
Other sessions of the program held on the first day
include Session 2 “The Path to New Industries in the
21st Century,” Session 4 “Overseas Activities,” and Session 5 “Innovative R&D.” There were 16 invited lecturers, including 8 from abroad, who made presentationsin the sessions. The following list shows lecturers fromabroad.
Jean Philippe Gouy / LIMMS / CNRS-IIS
Michael Gaitan / National Institute of Standards
and Technology
Ming Wu / UCLA
Masako Miyazaki / University of Alberta
Helmann Sandmaier / HSG-IMIT
Paolo Dario / Scoula Superiore Sant’ Anna
Young-Ho Cho / KAIST

6

The second day of the program was intended for theJapanese national project “Micromachine Technology”
under the Industrial Science and Technology Frontier
Program. Mr. Yoshikazu Yamaguchi, Director for Machinery and Aerospace R&D of the Agency of Industrial
Science and Technology reported the current status of
R&D activities under the project. He also introduced
the status quo and future prospects in conjunction withthree national research institutes, including the Mechanical Engineering Laboratory under the Agency ofIndustrial Science and Technology. Furthermore, Mr.
Tatsuaki Ataka, chairman of the R&D working group of
Micromachine Center presented state-of-the-art R&D
activities in the second phase. Four chief examiners of
the R&D working group of Micromachine Center disclosed the results of the technological trend surveys. Also
seven other presentations were made concerningachievements of the ISTF projects.
The planning and contents of the presentations inthis symposium were highly appreciated by the participants, as proved by their comments in the questionnaire
sheets collected upon completion of the whole program.
The schedule for the next symposium is shown below.
The 7th International Micromachine Symposium
Period: October 31 (Wed) to November 1 (Thu), 2001
Place: Science Hall, Science Museum in Kitanomaru
Park, Tokyo

View of Symposium Hall

From the 6th International Micromachine Symposium Special Lecture

Artificial Heart Research by the Use of
Micromachines
Sinichi Nitta
Vice President of Tohoku University andProfessor of the Inst. of Develop. Aging and Cancer
Good morning, everybody. My name is Nitta. I havelong been vice-chairman of the Medical Application
Working Group of the Micromachine Center. Naturally
I have been closely related to micromachines. I specialize in cardiosurgery, and am working in a boundary area
now popular, specifically in the area of biomedical engineering.
Today I have been requested to talk about micromachines and artificial organs, so will talk about whatcomes to mind. However, I am not confident about how
to relate micromachines to this lecture.
[Kinds of Artificial Organs and the Current Situation]
The artificial organs are now applied systemically.
For example, blood is pumped from the heart in the circulatory system to circulate through the whole body.
Every organ related to it falls under this category.
The use of heart pacemakers is now a well-established practice for the circulatory system. It was formerly
as big as 10 cm in diameter and 3 cm in thickness, but is
now miniaturized to a weight of only 20 g. Its battery
lasts as long as 10 years. It drives the heart by emitting
electricity periodically. As a cardiac surgeon, I often havea look at the heart by inching an optical instrument
through the chest. When I touch the heart lightly, itreadily reacts to this mechanical stimulus. It also reacts to a flow of electricity. The heart shrinks when electricity passes through it. The heart pacemaker is basedon this principle. If this device is rendered much smaller,
it will sooner or later be incorporated into the heart andenergized wirelessly from a device in or near the heart.
This will also depend on how micromachine systems
advances in the future.
Next comes an artificial valve. The heart is driven
by a pulsation. Naturally, valves are required at every
inlet. This valve is also manufactured artificially. It lasts
20 to 30 years in the human body.
Next, let me explain about an artificial heart in which
I specialize. An artificial heart is to be embedded after
the original heart has been removed from the humanbody. How long do you think it will last? May I ask thisgentleman sitting in the front. Two years? Great! You
are worthy of being at the top. The artificial heart we
made works for about two to two and a half years. However, there are several problems to be solved. One is theformation of a thrombus. When blood touches an artificial material, it judges whether the material is friend or
foe. On finding it is a foe, blood coagulates to concentrate on attacking it. This is what we call the formationof a thrombus. This should be prevented. The humanheart works by a pulsation. It is known now that a man
can live with a steady-flow pump, such as a centrifugal

pump. However, what God gave us is a pulse pump. Thispulse pump is subjected to a fatigue test, a pulsation of
100,000 times a day. No material on the earth can withstand a fatigue test of 100,000 operations a day for over
five years. This means that no artificial heart is available that can last over five years. This is a task imposed
upon us to find an answer to this problem. We are now
getting various kinds of materials of a living bodythrough gene manipulation, including cell engineeringand tissue engineering. So eventually, we will be able tomanufacture an artificial heart that will last over five
years or over ten years if cell engineering, tissue engineering, and organ engineering work to cover an artificially-made one, moving parts, and the parts to withstand a fatigue test. The current heart transplantation
has attained a five-year survival rate of 70 to 80%. If an
artificial heart surpasses the transplanted heart, whichlasts five years, we will be able to manage without relying on the human heart. The general ethical view prevailing in Japan is hindering the progress of heart transplantation. We researchers who are now developing artificial organs think it is ideal that God forgives us if we
succeed in managing without relying on the organs ofothers by manufacturing a heart more excellent thanthe one God gave us with God-blessed wisdom.
This circulatory system is directly connected to life.
For example, a man dies if his heart stops. This system
is very important, because a man dies if oxygen is not
supplied to the brain for three minutes. Another factor
to be considered is the contact with blood. This is very
specific, because artificial hearts will not work well unless a more advanced form is devised than other artificial organs.
Next, the respiratory system, where gases are exchanged. An artificial lung dominates this area. An example of lung transplantation survival was reported forthe first time in Japan by Tohoku University the other7From the 6th International Micromachine Symposium Special Lectureday. We make this artificial lung. We are researching
into an artificial lung even now. At present, a heart-lungmachine is used clinically, which can be used as long as
seven hours for heart operation with almost total safety.
However, an artificial lung poses a problem if the operation lasts longer. It is very difficult to make this unit
last longer. Our research into a built-in artificial lungare already under way. However, another factor weshould consider after the removal of the lung is that thelung is used for speaking. The lung is used for utteringwords. This mechanism of speaking should also be manufactured separately. The lung itself is very important,because it functions in various ways, such as the production of hormones. It is utterly impossible for us tocopy the lung. What we can do well is only to exchanges
gases. The current situation governing an artificial lungis that no artificial lung has been made available thatcan be used for a prolonged period of time because of its
contact with blood.
Then, the digestive system and artificial intestinescome next. Organs for the urological area should also
be considered. We are working to make artificial valves
for patients who are finding it difficult to urinate. Sincean artificial valve should open and close, we are using
shape memory alloys for the manufacture of artificial
valves for patients suffering from dysuria, and confirming whether they serve the purpose by using laboratory
animals. The test of laboratory animals is going on successfully.
Next, motor-related organs.
And the sensory system, which should desirably be
studied in preference to other areas. We have sensory
organs with which we can see, hear, and touch. We aretrying to replace this sensory system with a sensor system, which, for example, resembles the eyes of a robo
cop such as we see in the movies. However, the information those eyes are actually collecting is different fromwhat our eyes collect. We may copy a human system
when we think of a sensor system. It is desirable, however, that, if a microsensor system, for example, is capable of collecting the volume of information beyond thereach of a human system, this function should be utilized to the full. This should be a well-developed area.
For example, our brain thinks various things, issues
commands, and controls in various ways. The brain issues various commands through the neural system, suchas moving hands, raising blood pressure, and secreting
hormones. If we can intercept the commands midway toobtain the information and convert it to electric signals,
we will be able to do what the brain intends to do next
while thinking to do something. We are now doing thisby varying the quantity of electricity. The subject of thisinterface will come up later. I think this will be a mainarea in which micromachines take part in the future.
Then, the ear, the nose, the intestines, the esophagus, the windpipe, the lung, the liver, the ovaries, joints,
and artificial blood vessels. The artificial blood vessel isnearly perfected among the artificial organs in the circulatory system. The aorta and a blood vessel with a8large diameter are in the stage of nearly ideal perfection. What is left unsolved is that an artificial blood vessel does not expand as desired when it should expand
because of the difference between the properties of thehuman blood vessel and those of an artificial one. We
refer to this as the mismatching of a living body. Such athing has not yet been solved, but an artificial bloodvessel that lasts for a considerably long time has been
made available. However, an obstacle has not yet been
removed in the case of a slender blood vessel, say, with adiameter of 1 mm, an obstacle in which, when blood takes
a slender blood vessel as a foe, it coagulates there. I think
this may be a situation in which micromachines willplay an active part.
In addition, an eye, a tooth, an artificial heart, a valve,a pacemaker, an artificial kidney, the bladder, the urethra, the skin, and an artificial leg are the subjects ofstudy.
[The Artificial Heart]
Please allow me to dwell on the artificial heart inwhich I specialize. The artificial heart beats 100,000
times a day with a discharge volume of about 70 cc eachtime. A displacement of about 70 cc is therefore required
if we are to make a pulse pump. Its size is determinedin this way. A steady-flow pump and a centrifugal pumphave come to be used for men as well. When I started
studying artificial hearts, it was believed that a man
would not survive with a steady-flow pump. However, aman was found to survive. What makes the difference isthat, if a man is required to have 100 cc of blood per kg
of his weight for living, a steady-flow pump should havea capacity of 100 cc plus 20 cc. Conditioned as such, however, it is quite intriguing for us in that it can be miniaturized. A man has two pumps for the right and left
ventricles. God combined the two together, but the twolook like one. Actually, however, there are two pumps.
One is a low-pressure pump for sending blood to thelung, a low pressure equivalent to about 20 mm/Hg. The
other, the left pump, sends blood systemically with apressure equal to blood pressure. It therefore follows
that the pump should have a power as great as four tofive times. Since the right heart sends blood to the lung,it pulsates by breathing. When air is inhaled, the pressure in the lung becomes negative to allow blood to return with a rush. When the heart is checked, it stops
sometimes, for example, when struck with a catheter.
The patient is conscious, so he keeps breathing. Then,the breathing pressure only comes out in arterial pressure. When the patient is conscious, I tell him, “Cough alittle”, while his heart isn’t beating. He coughs, then hisheart begins beating again in some case in response tothis mechanical stimulus of coughing. Just coughing
raises the pressure to about 120. Such a thing occurs at
a place just outside the right heart. Therefore, I think asteady-flow pump will do for the right heart in the future, because it makes such pulses, though slow. As forthe left heart, a pulsating flow is better than a steadyone for making men and laboratory animals vivid. I dare

From the 6th International Micromachine Symposium Special Lecture

say vivid. If I am allowed to say so, a steady-flow pumpis very small, easy to make, and inexpensive. In the future, I believe, a steady-flow pump will be used for theright and a pulsating-flow pump for the left.
This is an artificial heart developed for the first timein the U.S. by Dr. Akutsu, now honorary chairman of
TERMO CORPORATION if I remember right. Since it
was made in 1957, its history is very short. Generally,
an artificial heart has only a short history usually lessthan half a century. At that time, a laboratory animal
could survive only 1.5 hours.
This was also made by Dr. Akutsu in 1975. In thismanner, we now have two artificial pumps. This pumpserved to help a calf survive experimentally 268 days.
However, when an artificial pump is embedded in a calf
for 268 days, the calf grows two times heavier. This
makes it impossible for this heart to answer the purpose.
[Current Problems Related to Artificial Organs]
The artificial organs we are now confronted with are
under study by researchers including myself who are
currently researching into an artificial heart nearly as
long as its history. The points at issue are how deftly we
can make very small artificial organs and how we canmake them serviceable for a long time without problems. I am thinking of having as many researchers as
possible participate in studying the extent to whichmicromachines can answer the needs so that ideal artificial organs can be made.
Therefore, we have summarized the defects andpoints at issue with the artificial organs now available.
They are too heavy and too big. These problems are indisputably the ones micromachines can answer. The sensors do not work as desired, either. Micromachines arealso good at this point. Moreover, they are not well controlled automatically. There are two kinds of controls:
one type of control is to have the unit fit the body itself
when embedded, and the other, to have the unit last
longer such as with an artificial heart, the durability ofwhich poses a problem. However, micromachines enable
the processing and control of information, thus dominating this sphere of activity.
They are not energy-effective, either. For example, I
am now developing an engine for medical treatmentusing a shape memory alloy. The shape memory alloy I
am now using is a commercially available large-diameter unit. I believe that if the alloy can be divided intovery small elements and then re-assembled, it will beeasier to control and be energy-effective. I am proposing this concept to the industry, but to no avail.
The engine has been completed in my head, but theindustry is quite reluctant in complying with my request.
Further, it does not last long. To make matterÇì worse,
unpleasant things occur one after another, such as noiseand vibration, accompanied by thrombus as a by-product. Since an artificial heart is a foreign body, it can also
become a source of infection. The human body reacts toforeign bodies in various ways. Bleeding also poses a

problem.
[Characteristics Desired for Upcoming Artificial
Organs]Desirable characteristics for newly developed artificial organs are, first, miniaturization, second, to interface with nerves for automatic control, third, to have acontrol system that is acceptable for both the living bodyand the embedded artificial organs, and fourth, to harmonize with the living body in various ways. Many issues have come up in the past, such as noise. Anotherdesirable characteristic for artificial organs is to last
several years. The artificial hearts now available last alittle over two years, but should desirably last longer.
Now, we have two large national projects in Japan,
led by the Ministry of Health and Welfare and NEDO.
We are setting about dealing with an artificial heart.
The project by the Ministry of Health and Welfare haslasted five years and will come to an end this year. We
hope it continues longer. As one of the members participating in the NEDO project, I am glad to know of thedecision to continue this project one more time.
Recent Research of Artificial Organs
This is an artificial heart we developed. It is stilllarge, but it has two pumps, right and left, in this form.
This shows how it was embedded in the thoracic cavity.
And this is an artificial heart equipped with amicrosensor, undoubtedly related to micromachines. I
think it is the first product in the world into which achip was inserted directly. It is a result of the work I did
about fifteen years ago together with Professor Esashi
at Tohoku University. Frankly, I was also a student ofProfessor Matsuo for one and half years, who was Professor Esashi’s teacher. So I started this work.
This is an auxiliary artificial heart. Pressure sensors are attached to the outlet and inlet, where they areconnected to the living body. This is an artificial bloodvessel leading to the aorta, and this is a duct. This is acannula with which to draw blood from the heart. Attached at the top in this manner is a microsensor. Hereis another. It is made in this manner, and its surface iscovered with an antithrombotic material so that blood
can hardly perceive it as a foreign body. It is about 20
microns thick, covering the sensor surface.
This is a diagram of the sensor itself. I am not a specialist in this field, but, according to Professor Esashi, it
is very difficult to connect a lead wire to a sensor. I think
the solution to this can be found by integrated molding.
Actually, it is being perfected. This is the surface of apressure sensor to be pressured. This is the rear side.
This is a connecting part. This is an experiment using agoat. This is a system to assist the left ventricle. This isa sensor. This is a trace of the micro-sensor after two
weeks.
We also have to measure the flow. This is a bloodflow meter using ultrasonic waves, developed jointly with
Cornell University. This is its trace, which is almost thesame as that of the conventional electromagnetic flowmeter.

9

From the 6th International Micromachine Symposium Special LectureThen, we use an artificial heart to assist the heart.
To ensure that the heart can set up for itself, we draw
two hysteresis curves of the left ventricle in this manner to connect them with a straight line. The more upright the inclination of the straight line, the more active is the heart. The more it declines, the worse is theheart. We therefore measure using a hysteresis curve to
see how active is the left ventricle. This necessitates
measuring pressure and the quantity of the discharge
from the left ventricle. By measuring the two, we canmeasure how active the heart is.
[Neural Interface]
Let me explain about the neural interface we justtalked about.
This shows the findings of the experiment using agoat. Above is aortic pressure. This is a neurogram, ameasurement of the integrated action potential of anerve. This is aortic flow.
Here, “stand up” is written. When a goat tries to standup, we can obtain neural information in advance. Thismeans that we can obtain neural information in advancewhen a goat stands up. With this method, we can manage well by accelerating the beat rate if we can judge
whether various kinds of artificial hearts are in a state
acceptable to the body and what should be done fromthat point. This means that we can get signals earlier
than God. In the case of God, it sends signals in likemanner to have an organ that raises blood pressure andsecretes hormones, which in turn raises blood pressure.
This takes dozen or so seconds. In the case of an artificial heart, however, we can control the above process ina few seconds instead of dozen or so seconds. This is
welcome for us. This kind of work is carried out infrequently, and we are the first in the world to take theinitiative.
This is a neural device for that purpose. It is madeinto a cuff containing a nerve so that the nerve is protected from damage when pierced directly. The cuff isalso a kind of interface used, for instance, for applying
electricity or stimulation. This is exactly the process bywhich the nerve is electrically converted to a control
system or for use as information. A new trial like thishas appeared. As I mentioned just before, this may explain the reason why a new trial like this to what wecall a sensor system will be applied more and more frequently.
[Microsensors]
With microsensors, we can obtain a variety of information on vital signs, including blood pressure, blood
flow, pulse rate, breathing condition, temperature, andchemical substances for artificial heart, such as glucose,
insulin, CRP and ammonia. The microsensors also enable us to obtain information from a living body, such as
the concentrations of oxygen and carbon dioxide in the
blood, pH level, and electrocardiogram. Those microsensors are embedded in the body, and driven elec-

10

tromagnetically. Our system also has them. In short, amicrosensor can send electricity into the body, a device
with primary and secondary coils wound around it.
Therefore, a microsensor can transmit power and information wirelessly without a cord piercing the skin evenwhen embedded in the body. Its efficiency is such that it
can send electricity with an efficiency of about 90% byincreasing flux density with an amorphous material in
our case. In the future, therefore, various devices will
be embedded in, for instance, the body of a sick patientor a postoperative patient, to be controlled intensively
at a given place. It is not necessary for those devices topierce the body for communication. We therefore assume
that, as with the artificial heart, we will eventually beable to go to an electric station after several decades
when we are short of electric supply in our daily life as
we now go to a gas station for gasoline.
At present, most of the microsensors are used for acatheter. It is desirable, however, that microsensors beembedded in artificial organs. If so, we can obtain a variety of information and use it for controlling.
This is a sensor that Esashi Laboratory is researching. This is a self-mobile active catheter, for insertion
into a blood vessel in the brain, which is one of our
projects we are doing our utmost to promote as members of the committee in the Micromachine Center. Since
artificial blood vessels are considered a hard nut to crack,
we are in the process of developing this, accompaniedby the development of various element technologies.
As I am a cardiac surgeon, we are thinking of embedding sensors in various parts of the heart. By so doing, we can understand well how a pump works. And
this is an artificial valve which stands for 20 to 30 years.
Since its movement is actuated by a difference in pressure, it moves only passively. If a micromachine can beused skillfully, a valve will come to open spontaneously
by controlling it with greater skill.
[Review of the Study of Artificial Organs in the 21stCentury ]In 2018 such as, for instance, an artificial kidney,
now used in vitro, will be made available for embeddingin the body. Here is what we call a hybrid. It will become possible to make what an artificial thing cannot
do by using various cells and tissues of the living body.
We are also expecting the emergence of a bio-cell byaround 2014 as researchers of artificial organs.
In this presentation today, we are looking forward to
the realization of artificial organs that are durable, reliable, stable, miniaturized, and biocompatible alongwith energy transportation or a battery system by utilizing micromachine technology.
Thank you very much.

(This paper is a summary of Prof. Nitta’s lecture, prepared by MMC.)

“Micromachine 2000” Held
The 11th Micromachine Exhibition, “Micromachine 2000”
was held with The 6th International Micromachine Symposium at the Museum in the Kitanomaru Park, Tokyo, for threedays from November 8 to 10, 2000. The exhibition met with an
enthusiastic reception.
The exhibitors include Micromachine Center and 22 supporting member companies of the center. A record number of
94 companies, organizations, universities, and research institutes joined the exhibition program from Japan and foreigncountries. This exhibition covered state-of-the-art
micromachine technology and results of researches. The sizeand contents of the exhibition have been highly valued year
after year as the largest exhibition specializing in micromachinetechnology, not only in Japan, but also in Asia.
This year’s exhibition disclosed and demonstrated all the
prototype systems created by the respective member companies which participated in the 10-year project “MicromachineTechnology” under the Industrial Science and Technology Frontier Program promoted by the Ministry of International Tradeand Industry. In other words, the exhibition was full of thecomprehensive achievements of the R&D activities conductedby MMC’s member companies over a period of 10 years.
The exhibited items on general exhibition included
micromachines, their components and applied systems, MEMSrelated systems, molecular machine related technologies,
micromachine manufacturing related equipment and materials, micromachine evaluation technologies andequipment. This
exhibition was intended for experts and specialists in such fields
as R&D, engineering, design, production, manufacturing, management, and administration of almost all industrial genres
such as machine and precision machine, electric and electronics, medical, information and communications, automobile andtransportation, biology, physics, chemistry, construction, steel,aerospace, ship and marine industries.
The exhibition is an ideal place for companies involved in
the R&D of micromachines to promote their technology, equipment and products. It is also a good opportunity for universities and research institutes to make the results of their researches known to the public. In addition, new companies in
the market find this occasion useful to introduce their products and technologies.
The exhibition was broadcast on several TV news programs.
For example, NHK’s “News 10” aired the exhibition report for

about 3 minutes from 10:30 p.m. on November 7, while Television Tokyo’s “News Eye” reported on the micromachine exhibition also for about 3 minutes from 5:30 p.m. on November 9.
On the same day, NHK Satellite 1 “Economy Frontline” on BS23
broadcasted a special report on micromachines for 8 minutes
from about 11:50 p.m. Furthermore, NHK’s “Good Morning
Japan” on General Channel 1 introduced detailed contents ofthe micromachine exhibition in terms of micromachines which
serve the micro world in its “Information Box” corner on themorning of November 15.
The broadcasts focussed on areas of achievements of thenational project “Micromachine Technology” including the “Experimental wireless micromachine system for inspection on
inner surface of tubes” (developed by DENSO CORPORATION,SANYO Electric Co., LTD. and TOSHIBA CORPORATION),“Experimental chain-type micromachine system for inspectionof outer tube surfaces “ (by MITSUBISHI ELECTRIC CORPORATION, Matsushita Electric Industrial Co., Ltd., and
SUMITOMO ELECTRIC INDUSTRIES, LTD.), “Micro Catheter” (by OLYMPAS OPTICAL CO., LTD.), and the world-smallest experimental system for micro processing and assembling“Microfactory” (developed jointly by Seiko Instrument Inc.,FANUC LTD., Hitachi LTD., Aisin Cosmos R&D Co., LTD.
YASKAWA ELECTRIC CORPORATION, Fuji Electric Corporate Research Institute, and MITSUBISHI CABLE INDUSTRIES, LTD.). Developers of respective systems were interviewed and the inner mechanisms and parts were described indetail.
There were a record number of about 5,500 visitors to thethree-day exhibition. The exhibition floors were crowded withenthusiastic visitors who spent a long time looking at the exhibited items and asking questions to booth attendants.

Exhibition full of visitors From Japan and abroad

Groups of elementary school children studying the exhibited items with enthusiasm

Schedule of next exhibition “Micromachine 2001” Exhibition is shown below.

“Micromachine 2001”
Period: October 31 (Wed) to November 2 (Thu), 2001
Place: Science Museum in Kitanomaru Park, Tokyo
Inquiry: Mesago Messe Frankfurt Corporation.
Tel.: +81-3-3262-8411 Fax.:+81-3-3262-8442
E-mail: micro@mesago-messefrankfurt.com
URL: http//:www.mesago-messefrankfurt.com/micro

11

Research on the Application of Sprout Technologies in otherFields to Micromachine Technology for Fiscal 1999 (Part II)
Since 1992, the Micromachine Center has taken up various seeds of technology as themes for joint research by academic,
governmental and industrial sectors, aiming to reinforce basic technologies by searching for technology seeds, especiallyin the scientific and technological fields, that are necessary to build various micro systems. In fiscal 1999, research has
been carried out on nine themes. Continuing from the last issue, the remaining five themes are summarized below.

Investigation of the Trend Related to the Fusion of Biosensor Technology with Micromachine Technology
Masuo Aizawa
Professor, Graduate School of Bioscience and Biotechnology,
Tokyo Institute of Technology
1. Introduction
The research and development of biosensors has rushed into
an age of upheaval. The main reason for this drastic change may
be found in the rapid diversification of needs for biosensor technology and the progress of related technologies.
In response to these diversified needs, targets of the researchand development of biosensor technology have been clarified as
described below:(1) On-site sensing, (2) massive information sensing, (3) complex information sensing, and (4) ultimate sensing technology. This
paper will describe what can be realized when biosensor technology is fused with micromachine technology, and it will investigate
the current status of the application of micromachine technology
to the foregoing items.
2. Massive information sensing and micromachine technology
The importance of molecular information about DNA andchemical substances has come to be recognized, which in turn has
led to attaching greater importance to massive information sensing technology with which molecular information contained in a
trace amount of sample can be analyzed at one time. Massive information sensing is used for or expected in the detection of DNA,evaluation of substances synthesized by combinatorial chemistry,and detection of environment-related substances. This paper summarizes the trend of massive information sensing related to theanalysis of gene information chiefly on DNA chips, and a report ispresented on the findings of the investigation of micromachinetechnology required in that field. Also summarized are the evaluation of molecular functions in combinatorial chemistry where massive information sensing is expected to develop in the future, thetrend of research in the micro total analysis system, µTAS, in neural network information sensing, and the application of micromachine technology.
3. Ultimate sensing and micromachine technology
Chapter 2 deals with the trend toward research of massive
information sensing and the utilization and technical problems of
micromachine technology. In addition to the micromachine technology chiefly related to processing, another micromachine technology for evaluation and observation is also available. This isprobe microscope technology (SPM), including AFM. In recent
years, SPM has developed rapidly as a technology for sensing
minute targets, and it is beginning to be utilized. Particularly fordeveloping research that delves into the constituents of microorganisms and materials a technology is required that will allow asingle molecule to be observed.
With this background, “a probe microscope”, which enables
topologic information to be obtained by probing for a sample without relying on light or electron rays, is considered essential as a
new technology by which observation and function measurement12

can be made possible on a single molecular level. This chapter
deals with the contribution of micromachine technology in the technology of sensing minute molecules and minute areas with emphasis on various probe microscopes to probe for single moleculesand single cells as their targets.
4. Bio-system microprobe
For those with health problems, the aged and disabled, it isnecessary to routinely monitor their health management information so that they can participate in social activities. For that
purpose, it is most effective to use a sensor embedded in a biosystem for measurement. This makes it inevitable not only to micronize a sensor device, but also to realize the application of thedevice using materials compatible with a living body. This paper
summarized the trends in research of microprobes that can beused directly for a living body along with tasks for which micromachine technology is required.
5. Conclusion
Research and development of biosensor technology has entered a new stage aiming at high performance by micronizationand integration. In a narrow sense, DNA chips and µTAS are notcategorized as sensing devices. With the enlargement of the baseof biosensor technology, however, they have had a strong impact.
In this investigative research, by assuming the future targets ofbiosensor research, the present state of related research was generalized after reviewing how micromachine technology can contribute to the achievement of those targets. Since the related research branches out broadly, its investigation was limited. However, many themes of research and development to be promoted in
the future have come to the fore.
Microprocessing technology is making rapid progress. However, sizes that can be processed at present are considered to be on
the submicron order. It will be necessary to transfer to a processing form unlike the present one if processing to the nanometerorder is required. Further miniaturization is needed, particularly
to permit a sensing device to be embedded in a living body. In
addition, the device should have a structure wrapped in a material compatible with a living body. Developing a technology capable of using various materials compatible with a living body as
the raw materials of micromachines or the importance of developing materials compatible with a living body, suitable formicromachine processing, is expected to grow in importance. Again,
for micronizing sensing devices, it is necessary to develop a method
suitable for modifying molecules (enzymes and antibodies) precisely into minute materials.
Currently, various research themes to be promoted in the future have surfaced. At the same time, it has been demonstrated
that the fusion of biosensor technology with micromachine technology is an important theme for development of future biosensor
technologies.

Investigative Study of Chemical Reactions
and Synthesis Using Microreactors
Jun-ichi Yoshida
Professor, Graduate School of Engineering,
Kyoto University
Microreactor technology has recently become a new andvery promising field within a very short time in the fields
of chemistry, process engineering, and biotechnology. The
application of micromachine technology to chemical synthesis is progressing at a particularly rapid rate. On finding that this technology could be realized, the chemical industries in Europe and the U.S. have aggressively set about
the trial manufacture and operation of microreaction systems in only a few years.
Downsizing as represented by microreactors is expected
to contribute greatly not only to future chemical synthesis
but also to industry and society as a whole. This has
prompted the investigation of chemical reactions and syntheses using microreactors with the emphasis on the nature of reactions, the manufactures of reactors and application to the development of functional materials and drugs.
Several organic reactions using microreactors have already been reported. Particularly noteworthy is the factthat microreactors, characterized by a large specific surface area per unit volume, could realize reactions hitherto
considered impossible to achieve. In addition, heterogeneous
catalytic reactions and electrochemical reactions that takeplace on a solid surface will develop dramatically using
microreactors in the future. Microreactors are also expected
to enable chemical manufacture using hitherto considereddifficult to use due to limitations of process engineeringand safety. What is more, microreactors enable the realization of a comparatively small-scale economical plant easilyand quickly when set in parallel, making it possible to transfer the findings of research and development more promptly
to the manufacture of materials. This will simultaneously
enable more rapid compliance with market demands.
The technology of chemical analysis or biochips, socalled micro-TAS or Lab-on-a-chip, can be used for manufacturing microreactors. However, other technologies will
also be required for the manufacture of microreactors suitable for chemical synthesis because of the great differencein the requirements for organic synthesis and those foranalysis and biotechnology. For example, technologies ofmaterials for reactors, joints and connectors that are resistant to solvents frequently used for organic synthesis will
become increasingly important.
The applications of microreactors to chemical synthesis involve the development and manufacture of functional
materials and drugs. In the former case, it is particularly
worth noting that, by the use of microreactors, the processof manufacturing functional materials, including
microcapsules, dispersion of micro-particles and polymers,
so far considered impossible to manufacture with conventional reactors, will be revolutionized. In the latter case,the development of new drugs by combinatorial synthesis
and their manufacture using microreactors attract our at-

tention. Although not many examples have been reported
in either case, great developments can be expected in those
fields in the future.
Our investigation, which emphasized the above points,
reveals that a potential of microreactors has not yet been
fully utilized, leaving much room for dramatic and revolutionary development in the future. It is, therefore, premature to completely forecast and evaluate the direction of
the development of microreactors. It is beyond doubt, however, that microreactors will bring about a revolution in
research, development and manufacture in the chemicalindustry, presumably wielding great influence on the future shape of the chemical industry as well as our entire
society. Microreactors will bring about a new paradigm ofscience and technology, leading to the creation of new disciplines and new fields of industry. It is indispensable forthe development of microreactors in theory, design, manufacture, reaction, and application to concentrate the intelligence in a variety of fields, including microfluidics,
microfabrication, process engineering, reaction engineering, microanalysis, catalyst and organic synthesis. Since
these fields spread widely over electric and electronic engineering, mechanical engineering, chemical engineering,
analytical chemistry, physical chemistry, and organic chemistry, they should be organized to work together. Although
the research into the application of microreactors to chemical synthesis is not mature in Japan. However, energetic
research and development should be made in the future inview of the growing expectations in this field.

Microreactionengineering

Analyticalchemistry
Syntheticchemistry

Microfluidics
Chemical
synthesis
using
microreactors

Microfabricationµ TAS
Lab on a Chip

Downsizingofchemistry

Biochemistry

Desktop Factory

New paradigm of scienceand technology

Creation of new disciplines
and new fields of industry

How material shouldbe created and how
material should bemanufactured canbe determined.
Medicine

Bio-engineering
Biology

Pharmacy
ChemistryFig. 1 Chemical Reactions and Synthesis Using Microreactors

13Investigative Study of Micro Heat Design
Technology
Takayoshi Inoue
Professor, Department of Mechanical Sciences and Engineering,Tokyo Institute of Technology
It is well known that many problems related to engineering and industry arise from poor heat design andcontrol. This also applies to micromachines, which may
break down unexpectedly as seen in malfunctions andfailures without a prediction of temperature and heatelimination needs based on appropriate heat design, andheat control based on the above prediction. For instance,
deformation due to thermal expansion of component
parts, changes in action characteristics at high temperatures, and the progress of corrosion can be cited. Thismay be attributable to the failure in a temperature prediction for the part that goes out of order and in heat
control stemming from poor temperature prediction. It
is important, however, to include an appropriate heat
design in the design stage.
In the heat design of micromachines as well, it isequally important as in the heat design of conventional
size machines to evaluate local heat value and thermalload along with the quantity of heat to be removed when
considering how to remove the heat generated. However, the distribution of temperature and heat conduction characteristics in an infinitesimal area have notbeen entirely clarified because of the very small size ofthe target machines. This may also explain why no effective cooling system has been satisfactorily established.
This investigative study reports on a technique formeasuring temperatures on an immeasurably shortscale, the importance of which should particularly beconsidered in the heat design and control of micro devices, a method for theoretical and experimental handling of contact and interface heat resistance at the component interface, and a technique for calculating heat
conduction for heat design.
In micro devices, the area in which temperature information is required is incalculably too small to handle
by conventional temperature measurement techniquesin many cases. This area may be characterized by requiring a technique of high-degree space resolution
measurement. Accompanied by progress in micro processing techniques, measuring techniques have also
made progress recently so that it can meet the needs formeasuring temperatures at sites in such micro systems.
In this investigative study, various techniques for measuring temperatures in the proposed micro areas were
investigated for analysis to compile a report on the findings, citing actual examples.
In addition to the foregoing, it is possible to list various problems in thermal engineering as specific to micro devices. Important among these is thermal resistance at the interface of dissimilar materials. Thermal
resistance stands for an index by which the difficulty of

14heat conduction is represented. It may safely be calleda physical volume that controls a rise in device temperature because of a large difference caused in an areawith a large heat resistance. For example, heat is transferred by conduction in device components such as substrates or thin film devices. However, as is clear from
Fourier’s law relative to heat conduction, a temperature difference is sure to be caused in the elements unless a material is present with an infinitely large thermal conductivity. This will result in the presence of athermal resistance, large or small, in those elements.
What is more, a temperature difference is caused at theinterface of the elements because of the presence of athermal transfer resistance that differs from the inside.
As is clear from Newton’s cooling law, no heat can betransferred unless a temperature difference exists between the perimeter of the device and the surrounding
environment as we see in the final removal of heat tothe surrounding environment outside the device. Particularly in the case of micro devices, because of the small
size of each device component, the contribution of thermal resistance arising from the heat of conduction inside those elements becomes relatively smaller andsmaller. Generally, thermal resistance at the interfaceof elements does not depend on the size of the device. It
therefore follows that thermal resistance at the interface comes to be regarded as relatively important. In
this investigative study, the considerations describedabove are classified into the following problems for discussion:
1) A surface-related problem at the interface, whichbecomes important in various film-forming processes.
2) A volume-related problem arising from an incomplete layer near the interface.
3) A problem at the joining interface where respective materials are present as if pasted together.
The surface-related problem is important, particularly at low temperatures. Explanation of this viewpointis therefore given. In addition, a technique for measuring thermal resistance is proposed in various ways forverifying the value of thermal resistance, obtained theoretically. This is also under study.
Further, it becomes necessary to study the techniqueof calculating heat transfer with all of these factors combined. It is possible to select a technique for the respective purposes, ranging from a technique of simple analysis for a basic order estimate to a more exact one thatsolves a three-dimensional energy equation numerically.
Those techniques and related problems are introduced
along with the concept of the thermal resistance.

Investigative Study of the Possibility of Greatly Upgrading
Micromachine Technology by Utilizing Physical Phenomena that Characterize the Mesoscopic Area
Tokio Kitahara
Professor, Mechanical Engineering,
The Faculty of Engineering, Shonan Institute of Technology
1. Introduction
Micromachine component parts are as small, ranging from1 mm to 1 µm, which is larger than an atom or a molecule by 3
to 4 orders of magnitude and smaller than conventional machine parts by 1 to 3 orders of magnitude. This area lies between the area to which a macro physical phenomenon model
can be applied, hitherto used by conventional technology, andthe area to which a micro phenomenon model is applicable,with atoms or molecules used as units, an area that has been
making marked progress in recent years.
The modeling and practical application of physical phenomena in this mesoscopic region is seldom seen except for thetechnology related to hard disk drives. It is indispensable tograsp physical phenomena in this area so as to establish methods for utilizing them so that micromachine technology cangrow into a basic industrial technology.
2. Physical phenomena and related research trends
In this investigative study, physical phenomena related togreatly upgrading macro mechanisms were itemized (Refer toTable 1). The items considered particularly important were
investigated relative to their research trends.
One of them is tribology. The coefficient of friction in themesoscopic region often grows into a large value, and interfacial force or the surface tension of a liquid film are closely related to this value.
Water repellency has much to do with minute surface structure and chemical factors. The contact angle between a liquidand a solid is related with the surface tension of the two.
Water repellency is exhibited when a liquid with a highsurface energy is combined with a solid having a low surface
energy. Again, it has been clarified that water repellency isenhanced when the minute structure on the surface of a solidor an air layer is formed.
The effect of viscosity on macro mechanism components
can be measured by the law of similarity if it is within therange where Newton’s viscosity law holds good. From the
Reynolds numbers of microorganisms, the Reynolds numbersof the micromachine mechanism parts are assumed to be below 1.
Many thin-film parts are used for micromachines. To measure their mechanical properties, it is necessary to make amodel in which the effect of the surface layer is considered. At
present, however, methods for measuring various mechanicalproperties are still in the proposal stage.
3. Application map and the status of research and development
There are physical phenomena that stand out in themesoscopic region work as a positive factor in some cases, andas a negative factor in other cases. Those phenomena were itemized into interfacial force, surface tension, viscous force, adsorption layer, and mechanical strength, and their relationshipto the basic technology and manufacturing technology of
micromachines and device system technology was arranged inorder as their application map.
Various surface forces lead to an increase in friction force
in tribology. It is reported that minute unevenness formed on
the sliding surface reduces friction. On the other hand, an attempt is being made to handle micro parts by taking advantage of the surface force. A traction drive is also considered byutilizing high friction force.
An example is reported in which the minutely uneven functional surface having super water repellency was used for sealing an axis. Viscous force can be considered applicable to simplestructure devices, including torque converters, brakes, and vibration dampers.
Various methods of joining are used for micro application.
Adhesives can be used as a substitute method for separable
thread fastening. An adhesion and tensile strength tester was
manufactured on a trial basis for butt adhesive joint of slenderaxes with a diameter of less than 2 mm. A strength of 18 MPs
was attained with an epoxy adhesive. This enabled confirmation of the possibility of adhering micro parts.
Many prototypes of micro fluid devices were manufactured
by taking advantage of the laminar flow, high heat transfer,and other characteristics of a micro fluid. In the µ-TAS, now
attracting our attention, the above characteristics are integrated.
4. Conclusion
In upgrading micromachine technology to a higher degree,
it is important to utilize and overcome physical phenomena inthe mesoscopic region. There are many cases in which usefulfunctions are exhibited, accompanied by multiple phenomena.
It will be necessary to grasp quantitatively their synergistic
and counterbalancing effects in the future.
Table 1 Main physical phenomena that stand out when micronizing
Items
Interfacial force
Surface tension
Adsorption (layer)
Viscous force

Super water repellency
Mechanical strength

Related matter
Van der Waals forces
Electrostatic force
Capillary phenomenon
LB film, surfactants, Stiction
Electric viscosity effect,
Magnetic fluid,
Low Reynolds number
Surface tension,
minute form on solid surface
Crystal size, crystal anisotropy

15

Summary of Investigative Study of the Possibilityof Innovative Gene Therapy by the Use of MicroKazunori Kataoka
machine Technology
Professor, Graduate School of Engineering,
The University of Tokyo
Interest is growing rapidly in gene targeting to deliver genes into the living body for the purpose of cancer
therapy, and the study of the delivery system is being
actively pursued utilizing liposomes, viruses, and cationic polymers as the carriers of genes. Those carriers
are required to have various functions, such as stability
in blood flow, accumulation inside the targeted cells,
transfer to cellular nuclei, and release of effective genes
inside the nuclei. An additional important point is theneed for those functions to be realized on the micro scale,say, in order of micrometers or nanometers so that they
can be used for a living body. In this sense, the carriers(gene vectors) for gene targeting, applicable to clinicaluses, that surpass the properties of viruses would be
worthy of the term “biomicromachines”. Recently, an accidental death was reported in gene therapy using
adenoviruses in the U.S. This poses a serious problem
for spreading gene therapy in the future. It is urgently
required to develop non-viral vectors with excellent
safety and transfer characteristics without relying onconventional virus vectors if gene therapy is to breakthe category of a hitherto-used special method of medical treatment and grow into a universal method of medical treatment, applicable to a wide range of diseases.
In this case, an active approach is increasingly desired from the fields of medicine and biology as well asfrom the field of engineering. This approach includes
the establishment of a chemical engineering methodology to grasp the trends in the bio-environment beginning with a vector design based on molecular assembly
engineering (artificial viruses), and the development of
new analytical techniques to measure quantitatively and

Design of a micromachine forbio-compatible gene delivery
Investigation items: 1), 2), and 3)

Intravenous
injection

Effective accumulation into targeted sites
Size < 100 nm

Investigation item: 4)

Selective transport
into targeted cells
Investigation item: 5)

Taking into
the liver

Achievement of effective
transfer into nuclei
Investigation item: 6)

Blood vessel system
Reticuloendothelial
system(RES)

Kidneyexcretion

Transfer inside the body avoiding
a mechanism to perceive foreign
bodies to the living bodyAchievement of targeted gene therapy

Investigation items: 1) and 7)

Investigation items: 2) and 4)

Figure Image of a micromachine used for intravenous
in-vivo gene therapy and study items

16

over time the behavior inside the cells.
In this investigative study, therefore, specialists inpolymer synthesis and researchers from the companies
that have succeeded in developing the materials for targeting carcinostatic agents. In addition, researchers who
have been carrying out the study of gene targeting carriers also individually participated in systematic investigation of the merits and demerits of the many trials
carried out thus far with the intention of establishing a
guideline for the design of micromachines for gene targeting.
The major study items are summarized below together with a diagram of the positioning of each item inintravenous in-vivo gene therapy:
1 method for introducing various genes and its commercialization
2 A technique for device surface treatment using biocompatible elements
3 A gene including association based on molecular assembly
4 Polymeric nanocapsules oriented toward gene vectors
5 Structuring of an environment-responsive material
system
6 Clarification of a DNA delivery system in the cell
7 Various technical problems and their solutions in invivo gene therapy
The author believes that a series of important points
as described below can be clarified thus to contribute to
the development of next-generation micromachines forgene delivery by carrying out the investigative study of
the above items.
A series of important points are: 1) structuring of
micromachines for gene delivery, 2) mounting of genes
onto micromachines, 3) grasping of movements inside
the body and accumulation in targeted sites, 4) establishing of routes into targeted genes, 5) clarification of
traffic inside the cells and the routes for transferring to
nuclei, and 6) release of mounted genes and gene expression.

Seiko InstrumentsInc.
1. The Challenge of Micromachine Technology
With the rapid advance of information technology,
the network society has been growing as never before
in history, and nanotechnology has attracted worldwide
attention. Seiko Instruments Inc.developed their original watch manufacturing plant and the company’s precision machining technology has served as the company’s
basic technological power. In other words, Seiko Instruments has had a close association with micromachinetechnology from the beginning. In the new century, we
consider micro nanotechnology to be one of our mostimportant technological assets, and will continue our
R&D efforts along with ISTF project.
2. Development of Micromachine Technology
Seiko Instruments Inc. is now doing its best to act
as the organizer of prototype system development andalso to promote its own machining technology based on
the utilization of probe microscopes as manager for thedevelopment of micro-factory technology under the ISTF
project “Micromachine Technology.”“Micro-factory” is a new production system with thecatch phrase “Small products by small machines.” Conventional production systems have been developed tosatisfy high-volume and high-speed production, with theresult that they have become larger in size. Micro-factory technology proposes to meet the social demand of
the next generation which advocates production systems
be changed to low-volume and wide-variety production.
At the same time, production systems should be in conformance with such environment-friendly requirements
as energy saving, space saving, and resource conservation. At present we are working on the second-phase
prototype system (see Fig. 1) which suggests to us thehigh feasibility of micro-factory systems in the near future.

Toshihiko Sakuhara
General Manager,
Corporate R&D Department

We have directed our R&D efforts related to machining technology as a part of micro-factory technology toward developing new machining methods instead of
merely targeting downsizing conventional machining
methods. For example, micro electrolytic machining andmicro optical machining, making use of Scanning probe
microscope (SPM) technology are being developed. SPM
technology is focused on as providing the means to examine objects at the atomic or molecular levels and also
as a type of nanotechnology tool. We are conducting R&D
activities involving this SPM technology as micro-factory machining technology. Fig. 2 shows an example ofmicro electrolytic machining, which has sub-micron resolution performance and allows both electroplating andelectrolytic etching (attaching and detaching) in a 1-mm2
area.
The other machining method, micro optical machining, uses near visual field light to prove its performance
beyond light diffraction limits. The micro piezoelectricmotor developed in the first phase of the project is under further study for expected commercialization.

Fig. 2 A gear manufactured by micro electrolytic machining technology (Diameter: 600µm)
3. Future Stances
While working for on ISTF project, we have established our micromachine technology as the fundamental technology. From now on we will continue our efforts
for commercialization of the developed devices, utilization of the technology in other applications, and application of the technology for the creation of new production systems.
Fig. 1 Second-phase micro-factory prototype system

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TERUMOCORPORATION
1. The Challenge of Micromachine Technology
Medical care in the future will have to meet suchpatients’ needs as alleviation of physical burdens, support of human dignity, and reduction of medical expenses. Medical issues will have to be solved with thehighest priority given to patients. In this sense, minimally invasive treatment methods are highly required.
Micromachine technology is indispensable for realizing
minimally invasive treatment methods. We have conducted our R & D activities based on our belief thatmicromachine technology will be the basic technology
for medical care in the 21 century.
2. Development of Micromachine Technology
TERMO has participated in the ISTF project “Micromachine Technology” and developed “Optically driven
free joint devices” and “Micro laser catheters,” along withwhich Terumo has advanced its own micro catheter technology and micro laser technology. A single micro laser
catheter, which is used in a narrow lumen such as abrain blood vessel or the like, can serve both diagnosis
and treatment purposes.
In the first phase of the project, we examined techniques for laying electric wires over the external surface of a catheter tube for the purpose of mounting multiple sensors while securing the lumen for inserting atreatment device inside. As a result, we have successfully mounted a thermistor or ultrasonic vibrator in theform of a chip on the outer surface of a catheter tip. We
also conducted a basic study for the utilization of a 2.8µm laser, which allows excellent absorption in humantissues so that safe treatment would be available in bloodvessels.
In the second phase of the project, we further developed the basic achievements attained in the first term.
We optimized the micro catheter by making it flexible
for higher operability. As for the micro laser, we implemented a micro laser head by integrating it onto theend tip of an optical fiber with the capacity of solid laser
vibration having a wavelength of 2.8-µm developed in
the first phase. Furthermore, we examined measuresagainst the heat generated on the laser head and reduced the diameter of the laser head so that it can beused in combination with the micro catheter.
As for the final structure of the optically driven free18

Akira Takahashi, Ph. D.
Senior Managing Director,
R&D Center

Photo 1 Prototype of optically driven free joint device

Photo 2 Prototype of micro laser catheter
joint device, we integrated a photoelectric converter and
SMA actuator into a single body.
3. Future Stances
In order to realize minimally invasive surgery treatment devices, micromachine technology plays an important role in downsizing those devices. We will do ourbest to realize such medical treatment through developing micromachine technology-based devices on thebasis of our achievements accomplished in the past.

IWMF 2000 Held in Switzerland
The second meeting of IWMF was held at the Golden
Tulip Hotel in Fribourg, Switzerland under the initiative of FSRM for three days, October 9 through 11, 2000
(see Photo 1).
 IWMF : International Workshop on Microfactories,  which had started on the initiative of the Mechani-  cal Engineering Laboratory of the Agency of In-  dustrial Science and Technology in December 1998  FSRM : Swiss Foundation for Research in Micro-  technologyIn the IWMF, two days were assigned to convention
and a total of 49 presentations were made during thisperiod, including 11 invited lectures, 17 oral presentations, and 21 poster presentations.
The number of presentations by country, excluding
the 11 invited lectures, were :10 from Japan, 10 from
Switzerland, 7 from Germany, 3 from U.K., 2 from the
U.S.A., 2 from Finland, 2 from France, 1 from China,
and 1 from The Netherlands. The member companies of
the ISTF project “Micromachine Technology” also participated in the presentations on seven topics as listed
in Table 1 below (including invited lectures).
The list of workshop participants counted 75 names,
and the number of participants by country were : 26
from Japan, 23 from Switzerland, 10 from Germany, 4from the U.S.A., 4 from U.K., 3 from Finland, 2 from

France, 2 from The Netherlands, and 1 from Russia. The
attendance from Japan and Switzerland was noticeablyhigh.
The oral presentation consisted of five sessions andthe number of presentations in each session shown below (including invited lectures).
(1) System Aspects of Microfactories: 5 presentations(2) Microassembly and Handling: 10 presentations(3) Micromachining and 3-D Microstructuring: 5 presentations(4) Links to Nanotechnologies, Innovation, Visions for
the Future: 2 presentations(5) Microfactories for Medical, Pharmaceutical and Biotechnological Applications: 6 presentations
In session (1) above, presentations focused on practical systems impressed the progress made in current
R&D activities.
On the third day of the workshop, a technical tour to
EPFL in Lousanne was held and following four laboratories were visited. (see Photo 2).
• Robotics and Parallel Kinematics• Micro-actuators Stick and Slip
• Micro-ECDM• AFM and STM Applications
The next IWMF will be held in Minneapolis, Minnesota, U.S.A. in 2002.

Table 1 Results of studies on the ISTF project “Micromachine Technology” presented at IWMF 2000
[Oral presentations](1) “Visual Inspection Mechanism for Microfactory” by O. Tohyama, Mitsubishi Cable Industries, Ltd.
(2) “Industrial Impact of Microfactory” by T Hirano, MMC (invited lecture)(3) “Development of Micro Stages for Microfactories” by T. Matsuo, Yaskawa Electric Corporation(4) “The Microfactory for Processing and Assembly” by T. Ataka, Seiko Instruments Inc. (invited lecture)[Poster presentations]• “Wafer Level Three-dimensional Integration Technology” by A. Satoh, Fujikura Ltd.
• “Development of Micro Servo Actuators” by H. Nakamura, Yaskawa Electric Corporation• “Micro Fabrication Using Electrochemical Machining” by M. Suda, Seiko Instruments Inc.

Photo 1 View of workshop meeting

Photo 2 Technical tour to EPFL

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Micromachine Asia Seminar
Micromachine seminars were held in Malaysia,
Singapore, and Thailand November 19 (Sun) through28 (Tue), 2000. Micromachine Center hold overseas seminars twice a year for the purpose of circulating information originating in Japan, collecting information
abroad, and promoting interaction between countries.
It was the second occasion for the Micromachine Center
to hold the seminars in Asia; the first one was conducted
in 1997.
The list below shows the Japanese lecturers andtitles of the seminars.
“MMC Activities and Prospect of Micromachine”
by Takayuki Hirano, Micromachine Center“Multiple Distributed Micromachine Systems”
by Munehisa Takeda, Mitsubishi Electric“In-pipe Wireless Inspection Micromachine”
by Hideaki Nishikawa, Denso“The Experimental Microfactory System inJapanese National R&D Project”
by Kazuyoshi Furuta, Seiko Instruments“Medical Application of Micromachine”
by Takashi Mihara, Olympus Optical“Novel Actuators for Microrobots”
by Koichi Suzumori, Micromachine Center(2) Singapore-Japan Forum on MEMS
The forum was held in Singapore on November 23(Thu), 2000. “Gintic” which cooperated with MMC for
the forum is a national research institute established
as an independent institute out of Nanyang Technological University. Gintic conducts research activities for
production technologies in various industrial fields. The
seminar was held at the Grand Hyatt Hotel located at
the center of Singapore. It was a success with about 90
participants from institutes, universities, private companies, and government organizations throughout
Singapore. In addition to the 6 Japanese lectures, presentations by Singapore University and Nanyang Technological University were given. Those included “ MEMS
Tunneling & its applications,” “Microgyroscopes andpackaging process,” “MEMS simulation technology,” and“Optical MEMS.”(1) Seminar on Micromachine Technology
The seminar was held in cooperation with SIRIM
Berhad in Kuala Lumpur, Malaysia on November 21(Tue), 2000. SIRIM is an organization owned by the
Malaysian government and responsible for the standardization of industrial technologies and R&D activities. A
total of 47 participants from organizations related to
SIRIM and Malaysian universities joined the seminar.

(3) Micromachine Technology Seminar
The seminar was held in Bangkok, Thailand, on
November 27 (Mon), 2000, as part of an education program hosted by Technology Promotion Association (TPA).
TPA was established for the promotion of technologicalexchange programs between Thailand and Japan by
Thai engineers and business men/women who had once
studied or worked in Japan. The seminar was attended
by 28 enthusiastic participants from Thai companies anduniversities etc.
The atmosphere and manner mentioned above differ from one country to another. However, these countries without exception seemed to be actively promoting the new technologies and their industrial application.

Seminar in Malaysia

Seminar in Thailand

The following reports were on the respective seminar events.

20

After the keynote speech by Dr. Othman, vice-presidentof SIRIM, 6 lectures were made by Japanese, who received a lot of technology related questions.

2000 Micromachine Asia Mission
During the Micromachine Asia Seminar, we visited
related institutes in each country and exchanged views
with the respective representatives as reported below.
SIRIM Berhad
Location: Kuala Lumpur, Malaysia
Date: November 20 (Mon)
Attended by: Dr. Mohd Shazali Hj Othman, Mr. Yahayabin Ahmad, et al.
SIRIM Berhad is a Malaysian government institutefounded in 1975, and has been responsible for the standardization of industrial technologies and R&D activities. In 1996 it was incorporated though owned by the
Malaysian government. The institute also offers assistance for technical transfer to small and medium sizedcompanies. The institute also takes great interest inproviding technological assistance to small and medium
sized companies.
We visited a computer training room, machine shop,and show room, where prototypes of automobile battery
chargers, welding robot jigs, and draft machines for batik (cloth) were exhibited. The representatives told usthat the institute was willing to include micromachinetechnology and other state-of-the-art technologies intheir activities on the condition that such technologies
would support businesses.
Gintic Institute of Manufacturing Technology
Location: Singapore
Date: November 24 (Fri), 2000
Attended by: Dr. Wang, et al.
Gintic is an institute on the premise of Nanyong
Technological University in the outskirts of Jurong City
which is about 20 km west from Singapore City. The
research division consists of three sections, Automation
Technology, Manufacturing Technology, and Process
Technology sections. The institute currently has 375 staff
members (70% of them are researchers) and is operated
with a 60 million dollar annual budget for research
projects.
Nanyong Technological University
Location: Singapore

Tour to SIRIM

Date: November 24 (Fri), 2000
Attended by: Dr. Miao Jianmin, et al.
The Micro Machine Laboratory of Nanyong Technological University was established as an attached laboratory to the Mechanical Engineering Department of
Nanyong Technological University three years ago. The
laboratory has 12 researchers, 5 research fellows, andabout 20 students. Their 200-m2 clean room is equippedwith the complete set of equipment necessary for MEMS.
Researches related with acceleration sensors, fluid devices, optical devices, TiNi micro grippers, etc. are being
conducted. The achievements of this laboratory will serve
the country greatly from now on.
The National University of Singapore
Date: November 24 (Fri), 2000
Attended by: Prof. Francis E. H. Tay
We visited Dr. Francis E. H. Tay’s MEMS Laboratory in the Mechanical Engineering Department of the
National University of Singapore. At the MEMS Lab
we were briefed on their researches on the microgyrousing tunnel phenomena, micropositioner, micropumpwith a bimorph actuator (targeted at insulin medication application), and oscillatory pressure sensor. The
laboratory has obtained a lot of patents for oscillatory
microsensors. For manufacturing sensors, the laboratory uses Cronos’ foundry service.
Economic Development Board
Date: November 24 (Fri), 2000
Attended by: Mr. Wong Peng Wai, et al.
We visited the Economic Development Board (EDB)
and exchanged views and related information with therepresentatives on micromachines and MEMS. EDB isan organization under the Singaporean Ministry ofTrade and Industry.
The meeting session was not only participated in by
EDB staff but also a lot of people from universities, research institutes, and companies related with this technology. They explained the state-of-the-art technology
development in Singapore and the commercializationplans of new technologies including micromachines/
MEMS were discussed.

Tour to GINTIC

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Latest Micromachining
Technology — Part 4
Reproduction of Small Shapes — Molding
Technologies
Professor Kazuo Sato
Department of Micro System Engineering, Nagoya University
In this last part of this series of lectures, I would like todeal with technologies to transfer microscopic shapes, which
are fabricated by the methods discussed previously, in othermaterials. These technologies feature two outstanding effects
as follows: (1) The mass production of microscopic parts is possible. (2) Micromachining using various types of materials including silicon becomes possible. These technologies will be thebasis for a number of applied micromachine technologies to be
introduced into industries of different genres.
1. Transcription of etched shapes
By etching a pattern on a silicon single crystal substrate
and molding the shape on the surface, a 3-D structure of adifferent material from the substrate can be formed. For example, nonplanner structures can be created with films suchas silicon dioxide or silicon nitride. Fig. 1 shows an AFM-probe
chip made of a silicon dioxide film with a thickness of 1.2 µm.

Fig. 1 AFM-probe chip made of silicon dioxide film 1.2 micron thick having a bend tip.
To produce a structure with a bend tip, steps equivalent to bendcross-sections are formed on the surface of the silicon substrate.
Next, the entire surface is oxidized. Then the surrounding oxide film and silicon substrate are selectively etched away leaving the profile of the probe.
It is also possible to transcribe the shape on a silicon single
crystal substrate, where deep recesses are machined by an etching method, in polycrystalline silicon film. In the second partof this lecture series, an example of a film structure with a Tshaped cross-section in connection with the technology to produce a high-rigidity structure with a film was introduced. In

22

Fig. 2 Cross-sectional view of a fabrication process of a honeycomb structure made of polycrystalline silicon film.
addition to these, a honeycomb type film structure is also available. Fig. 2 shows the cross-sectional view of the fabrication
process of a honeycomb type film structure. A film structure isseparated after processing a silicon single crystal substrate witha large depth-to-aperture ratio (aspect ratio) by reactive ion
etching (RIE: Refer to the first part of this lecture series), laminating a sacrificial layer such as a silicon dioxide film and structure material such as polycrystalline silicon film in order overthe substrate surface entirely, including inner surfaces of recesses, and finally etching away the sacrificial layer selectively.
Through this procedure, a honeycomb structure with a thickness of 100 µm is produced with a film with a thickness of 1 to
2 µm.
In the field of biochemical technology that is expected to be
one of the micromachine applications, disposable micro fluid
devices are currently in demand. To meet such application purposes, the shape of a micro fluid channel created on a silicon
substrate by an etching method is transcribed in styrol resinetc. for mass-replication. The technology to transcribe microscopic shapes, or replication technology, itself is not new. For
example, in the field of spectroscopic devices, the technology oftranscribing a surface profile of diffraction grating which ismechanically engraved on an aluminum film with a pitch of
0.1 µm in resin material has already been established.
2. Reproduction of shapes developed in photoresist
Fine patterns are developed in a thick photoresist layer by
exposure to light to create micro cavities. Metal is depositedinside the cavities by electroplating method to produce micro
metal parts.
2.1 LIGA process
The LIGA process was developed by Karlsruhe ResearchCenter, Germany, in 1986. LIGA stands for the three processes
mentioned below, using initials of German words.
(1) Cavity formation by lithography (Lithografie in German)(2) Molding of cavity by metal electroplating (Galvanoformung
in German)(3) Reproduction of metal mold shape in resin by injection molding (Abformung in German)
Fig. 3 illustrates the cross-sectional view of steps (1) and(2) in the LIGA process above. This process features the use of
Fig. 5 Example of a molded plastic part made by using the
LIGA process (Courtesy of Brother Industries, Ltd.).

Synchrotron radiation
Mask substrate
Mask pattern
PMMA photoresist
Metal substrate

PMMA (after developing)Electroplated metal(Ni)

Finished productFig. 3 Cross-sectional view of the LIGA process.
synchrotron radiation (SOR) in place of ordinary UV light. With
SOR used, exposure of the 2-D mask pattern is deeply and accurately made in PMMA-system photoresist with a thicknessof several millimeters. By developing this pattern, a cavity withan aspect ratio in excess of 100 is formed. A metal structure asshown in Fig. 4 can be processed by electroplating the inside of
the cavity and reproducing the shape. The structure in thisphase can be directly put into practical use. However, by performing injection molding of plastics (Fig. 5) with the structure of a die, and reproducing the shape with electroplating
further applied, or using the structure for ceramic molding (solgel method), the structure can be applied to various types ofmaterials.
The high-precision processing accuracy of the transcription technology as represented by the aspect ratio is used insuch applications as optical communication devices, for example
3-D grating (diffraction grating) or optical waveguide, andchemical analysis devices with fine fluid channels.
The challenge in using the LIGA process is the limitationthat it cannot produce anything without SOR equipment. It istrue that the original die must be prepared by the use of SOR
equipment. However, once the master mold is prepared, thefollowing processes can be set for mass production. In Japan, aresearch team at Himeji Institute of Technology following theteam at Ritsumeikan University has successfully started the
LIGA process using radiation equipment.
2.2 High aspect ratio UV photoresist
Now available is a new type of photoresist that allows forhigh aspect ratio exposure and development by ordinary UV
exposure techniques, though the processing accuracy is lower
than that of the LIGA process. For example, SU-8 photoresist
developed by IBM can be exposed to a layer depth of several
hundred microns by the UV light method. The transcription
process using plating technique of the shape of the cavity after
exposure and development process is identical to that used in
the LIGA process.
Though even oxygen plasma cannot easily decompose thephotoresist resin for removal, the fact that UV exposure can beused is an advantage. Besides, the transparency of the resin isvery high allowing the product to be used directly as an opticalcomponent material regardless of the transcription technique.
Summary
With transcription technologies of microscopic shapes, 3-D
structures can be made of films. In addition, microscopic shapes
can now be created from such materials as metal, resin, andceramic. Increased material diversity is expected to expand theapplication range of micromachine technology.

Fig. 4 Micromotor structure made of Ni by the LIGA process(Courtesy of Prof. S. Sugiyama of Ritsumeikan Univ.).

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Preliminary Announcement
The 7thInternational
Micromachine Symposium
October 31 and Novemver 1, 2001
at Science Hall, Science Museum, Tokyo, JAPAN

Exhibition

MICROMACHINE2001
October 31 -November 1, 2001
at Science Museum, Tokyo, JAPANThe Detail will be announced later.

:

Pictures on the cove
coverr Winning artworks in the Micromachine Drawing Contests

Any language is OK, Mini Japanese translator, Threader, Communication Machine, Mini-mini barber (from top to bottom)
MICROMACHINE No. 34

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
Internet Home Page http://www.iijnet.or.jp/MMC/
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: February 20, 2001
© All Copyrights Reserved by MMC

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