IP: Some MicroMachine Activities in Japan

[Dave Farber <farber () central cis upenn edu>]

Copyright (c) 1996 by the Asian Technology Information Program (ATIP) 
This material may not be published, modified or otherwise redistributed in
whole or part, in any form, without prior approval by ATIP, which reserves
all rights. 






                  MICROMACHINE ACTIVITIES


INTRODUCTION.


A micromachine is an extremely small machine comprising minute (several
millimeters or less) yet highly sophisticated functional elements that allow
it to perform delicate and complicated tasks. Micromachines have many
potential uses across many industrial spectra, particularly in areas
demanding sophisticated, advanced maintenance technology in response to
increasingly complex and precise machine systems, and advanced medical
technology for remote surgery. Japanese government and industry have been
doing R&D in the field of micromachines for several years. For example, a
ten year project supported by MITI was begun in 1991, and coordinated by the
Micromachine Center, with the following topics specifically mentioned.


 1) Advanced Maintenance System for Power Plants
 2) Medical Micromachines
 3) Microfactories Engineering


A series of reports on the topic of micromachines appears on the ATIP WWW
site, www.atip.or.jp, dating back to the early 1990s. The current report is
not a comprehensive update, but a snapshot, as follows.


* A report by Dr. Jay Lee, of the US NSF, based on an extensive visit to a
number of Japanese research laboratories, over a six month period
(June-December 1995).


* A summary report by Dr. Tanya Sienko, of the First International
Micromachine Conference, which was held at the Japan Science museum in Tokyo
on November 1st and 2nd, 1995. Readers should note, the conference title
notwithstanding, there have been other micromachine conferences, for
example, The Micromachine Symposium, Nov 1994, Tokyo Japan.






                    MICROMACHINES IN JAPAN
                      (Dr. J. Lee, US NSF)


At the threshold of the 21st century, manufacturing industries in the world
are challenged by a set of common issues: aging population, environmental
protection, and manufacturing globalization.  As Japan continues its
leadership in manufacturing toward the 21st century, innovation is needed to
create new high value-added industry.  Currently, government and industry
are undertaking many major initiatives to implement new manufacturing
technologies and striving to maintain Japan's leadership for the future.


MICROMACHINE AND MICRO MANUFACTURING TECHNOLOGY


A micromachine is an extremely small machine comprising minute (several
millimeters or less) yet highly sophisticated functional elements that allow
it to perform delicate and complicated tasks. Micromachines have many
potential uses across many industrial spectra, particularly in areas
demanding sophisticated, advanced maintenance technology in response to
increasingly complex and precise machine systems and advanced medical
technology for remote surgery. Micro manufacturing is a process which
consists of a variety of micromachines to make micro mechatronics products.
In the United States, similar research activities such as the
Micro-Electro-Mechanical System (MEMS) and Micro System Technology (MST) are
primarily focusing on the manufacturing of micro devices integrated with
microelectronics devices on the same substrate, such as air bag sensors.  In
contrast, research activities in Japan focus more on micro engineering and
micromachines for mechatronics manufacturing such as micro motors, micro
gears, micro pumps, and micro robots for medical and industrial
applications.  Meanwhile, Sumitomo Electronic Industries Ltd., utilizing a
similar small facility, has developed a technology for fine-scale processing
of ceramic parts for micromachining.


The Micromachine Center (MMC) was founded in January 1992 to promote the
MITI Micromachine Technology Project.  The project funds are given by the
MITI to NEDO (New Energy & Industrial Technology Development Organization)
which, in turn, awards funds to the Micromachine Center.  The latter then
contracts to individual companies. Three government institutes have been
participating in the project, namely, the Mechanical Engineering Laboratory,
Electrotechnical Laboratory, and National Research Laboratory of Metrology.
Three industrial applications were selected for phase I of the project
during 1991-1995 at an amount of 10 billion yen.  They are as follows:


1) Advanced Maintenance System for Power Plants


This is a micromachine system for the maintenance of fine tubes in power
plants.  The system consists of a microcapsule, a base machine, an
inspection module and an operation module.  Necessary mechanical components
(e.g., microscopic power generator and energy transmitter) of the system
have been specified.  The component devices are being fabricated.


2) Medical Micromachines


Micromachines are applicable to examination and treatment inside the body
cavity.  A micromachine will possibly be inserted through a catheter for
diagnosing and curing, for example, cerebral thrombosis and aneurysm.
Component devices of such medical machines are being fabricated.


3) Microfactories Engineering


A system for manufacturing tiny precision parts of watches, cameras, and
electronic appliances with much smaller production equipment is needed.  The
system will greatly reduce energy consumption in production.  The miniature
equipment should be no larger than 2-10 times the size of the product.
Component devices of the equipment are being fabricated.


Selected Micromachine Research Activities in Japan


Traditionally micromachining has been mainly applied to the fabrication of
micro sensors and micro actuators using silicon as the substrate material.
However, technologies are required to fabricate mechanical structures out of
metals, ceramics, and other materials using evolutionary CAD/CAM processes.
Processing knowledge in micro machining, micro assembly, and micro
inspection needs to be studied to investigate the feasibility of
manufacturing micro products.  Some selected current research activities are
described as follows:


1) Micro-Grinding of Micromachine Parts


The development of micromachines requires first the production of very small
machine parts, i.e., micromechanical components, which are then used to
produce miniaturized machine mechanisms.  These components used in
sub-millimeter systems and micrometer systems must be produced through
conventional machining methods.  A micro-cylindrical grinding experiment was
performed using a small precision lathe.  A gear-shaped micro component with
a diameter of 0.5 mm in diameter has been ground by using a miniaturized
cylindrical micro-grinding machine.  The Mechanical Engineering Laboratory
of MITI has successfully demonstrated the fabrication of a micro gear by
using a cylindrical micro-grinding operation.


2) Micro Assembly


Micro assembly technology is a new and still undefined term. This term may
be used in different ways by researchers in different fields.  In general,
today's semiconductor processing technologies, such as photolithography and
the LIGA (Lithographie-Galvanoformung-Abformung) process, are used for
manufacturing but not assembling micromachine parts. Micro assembly
technology is an important future technology for assembling micromachine
parts into a module or system.  To achieve this goal, gripper and
manipulator are used to hold small objects.  Other manipulation methods
using electromagnetic or ultrasonic fields and atom handling also show
promise.  Bonding is another potential method for producing micromachines.
It includes the technology for bonding a group of devices collectively in
wafer levels as well as the technology for bonding each component
sequentially.  By this method, sample structures containing an internal
cavity, such as capacitive pressure sensors or micro pumps have been
produced at the Mechanical Engineering Lab of MITI.  Prototypes have been
demonstrated by companies such as Matsushita, Toshiba, Hitachi, and Fuji
Electronics.


3) Micro Inspection


In addition to the micromachining and micro assembly technologies, the micro
inspection technology is another critical area to support the micromachine
system.  This involves research into microsensors, microactuators, and
micromotion control systems.  Nippondenso has developed a micro inspection
machine which is packaged with a light-weight thin film structure.  It
includes a piezoelectric actuator which moves the inspection machine
backwards and forwards.  An eddy-current flaw sensor, which is capable of
detecting cracks of a few micrometers, is mounted on the machine.  The
micromachine has a diameter of 5.5 mm and weighs about 1 gram.


Case Example-Microcar


Nippondenso's microcar was produced with precision machining and
semiconductor process technologies. The intention was to demonstrate the
abilities and potential of the micro processing technology, by manufacturing
a car which is one-thousandth of the size of an actual car.  In the
beginning, Nippondenso was unable to incorporate gears into the car body.
The latest model has a micro motor 1 mm in diameter.  With power supplied by
a 25 micron copper wire, the car runs smoothly at a speed of about 1 cm/sec
with 3V voltage and 20 mA current.  The body is made through electroless
nickel plating and sacrificial layer etching, and the surface is gold
plated.  It is 30 microns thick yet strong enough to be picked up by the
fingers.  The microcar is a successful example of the 3D fabrication of
micromachine manufacturing technology.


The minicar was not able to run due to the heavy body weight.  As a result,
a thin shell structure was produced to modify the design.  First an aluminum
male die with three-dimensional sculptured surfaces using a machining
center, plated it with an alkali solution, and obtained a body structure
made of nickel thin film.  The body was finally completed by gold plating.
The completed minicar with shell body structure has a length of 4.8 mm,
width of 1.8 mm, and height of 1.8 mm. Benefits gained from the fabrication
of the microcar include improvement of the dimensional accuracy for
three-dimensional sculptured surfacing, techniques for reduction of damage
to machine surface, and methodologies for making minute molds and dies
through conventional CAD/CAM processes.  In addition, understanding was
obtained on assembly technologies including the fixtures, tools, and bonding
which are critical elements for the microfactory system.


Future Prospects


Standardization through international cooperation is an urgent issue.
Countries involved in micromachine technology should begin discussions aimed
at developing standardization procedures. In addition, advances in
exploitation of applications, in parallel with research and development,
will accelerate the research on micromachines.  Micromachine technology is
now being applied in various fields where microfabrication is combined with
conventional technologies.  In the next five years, I foresee that
integrated micromachine systems will be put into practical use for medical
purposes and instrumentation.  A processing industry based on processing and
assembling technologies as well as a functional device and machine
manufacturing industry should be cultivated to accommodate many new fields
of application.




========================================================================


 [The remaining sections of this report are available to ATIP subscribers]




Tokyo Office:  Asian Technology Information Program (ATIP)
               Harks Roppongi Building 1F
               6-15-21 Roppongi, Minato-ku, Tokyo 106
               Tel: +81 3 5411-6670; Fax: +81 3 5411-6671


U.S. Office:   Asian Technology Information Program (ATIP)
               c/o University of New Mexico US-Japan Center
               1601 Randolph Drive SE, Suite 200S
               Albuquerque, New Mexico 87106
               Tel: (505) 277-1474, -1490;  Fax: (505) 766-5112


For further information
    Send email to            : info () atip or jp
    Access WorldWideWeb Site : http://www.atip.or.jp/


ATIP: A collaboration between the US National Institute of Standards and
Technology (NIST), and the University of New Mexico (UNM).
========================================================================
[Complete ATIP reports on Asian Science and Technology go to subscribers
and collaborating organizations by direct distribution, or via electronic
access. These contain text and often, charts, graphs and pictures. Reports
for unrestricted distribution often contain summarized, or abstracted
information. Sponsors can also obtain specific follow up information -
including copies of proceedings, selected papers, exhibition particulars,
updates, translations, query searches, etc. Contact ATIP at
INFO () ATIP OR JP]