From: rick@cs.arizona.edu (Rick Schlichting)
Newsgroups: comp.research.japan
Subject: Kahaner Report: Background on micromachine activities in Japan
Date: 15 Oct 92 04:36:31 GMT


  [Dr. David Kahaner is a numerical analyst on sabbatical to the 
   Office of Naval Research-Asia (ONR Asia) in Tokyo from NIST.  The 
   following is the professional opinion of David Kahaner and in no 
   way has the blessing of the US Government or any agency of it.  All 
   information is dated and of limited life time.  This disclaimer should 
   be noted on ANY attribution.]

  [Copies of previous reports written by Kahaner can be obtained using
   anonymous FTP from host cs.arizona.edu, directory japan/kahaner.reports.]

To: Distribution
From: 
 David K. Kahaner
 US Office of Naval Research Asia
 (From outside US):  23-17, 7-chome, Roppongi, Minato-ku, Tokyo 106 Japan
 (From within  US):  Unit 45002, APO AP 96337-0007
  Tel: +81 3 3401-8924, Fax: +81 3 3403-9670
  Email: kahaner@cs.titech.ac.jp
Re: Background on micromachine activities in Japan
14 Oct 1992
This file is named "micromac.92a"

ABSTRACT. Japan's expectations for their large micromachine project are
described. First applications will be in medicine. Computer modeling can
play a vital role in the basic research. 

In several earlier reports, ["micromac.92", 22 Sept 1992, and
"micro.mac", 11 Sept 1991] I described a new Japanese government project
to perform research and development in the field of micromachines. Here
we fill in some background on the expectations and key problems. It is
clear that the main applications will be firstly within the medical field.
To develop the needed technology, computing, materials, electronic
device manufacturing, and other areas will need to contribute.

MICROMACHINES      

Intelligent micromachines for use in medical treatment and other
fields are of increasing interest, and research for the purpose of
producing  micromachines continues to flourish in Japan.  There is a
close connection between so-called intelligent materials and
micromachines, in the sense that intelligent materials can become the
materials for producing micromachines and their smaller versions, which
should be called nanomachines.

The world of micromachines is one where the basic parts have dimensions
that range from 10nm to 1mm.  Obvious applications of micromachines are
in medical treatment, post-assembly precision machinery, and in cases
where precise work must be done in special kinds of environments such as
high pressures, vacuums, etc., such as the ocean or in space.  But, at
least in Japan the use of micromachines in medical treatment is thought
to be the most concrete application area.

Japanese reports show concrete images of potential micromachines used in
medical treatment.  For example a drug transport vehicle.  Conventionally,
the entire body gets a drug dose, whether given orally or by injection.
This can limit the use of strong, potentially toxic drugs.  One approach
is research on drug delivery systems (DDS) which deliver drugs in
appropriate ways, in order to focus the effects of the drugs in specific
places and only for specific lengths of time. Another example relates to
micro-robots.  It ought to be possible to go through tubular cavities
such as blood vessels, the spinal cord cavity, etc., with a micro mobile
robot. Then surgeons could insert a tiny laser endoscope into the
diseased part and then a small manipulator attached to the end of the
endoscope could cut out only as little as necessary of the diseased part
of the body. If successful this will have a major impact on surgical
techniques.  Of course, in addition, if advances are made in
micromachine technology, there will also be dramatic progress in
miniaturization, flexibility, and functions of artificial organs.

The problems that arise in micromachine design technology as a result of
size are the marked increase in frictional resistance, viscous
resistance, surface resistance, and the noticeable decrease in strength.
In this areas, it is felt in Japan, that we must understand our bodies
in different ways than in the past.  In the actual design phase,
rigorous computer simulation and is felt to be essential. In this
regard, I have not seen any significant research related to computer
modeling of micromachines in Japan.

As for "micromachining," the technology for producing micromachines, in
addition to applying the fine processing technology used to produce
semiconductors, methods that involve using protein engineering and
atomic manipulation to assemble molecules and atoms together will also
be needed.

One recent example of micromachine production technology is the trial
manufacture of cantilever-beam-type actuators that mimic the ciliary 
movement of living organisms.  Each of these actuators consist of a 
cantilever made from two kinds of polyamides that have different rates of 
thermal expansion, and a metallic resistance wire sandwiched between two 
polyimide sheets. In their initial state the cantilevers curve up about 
250 microns from the substrate because of the residual stress.  When 
current flows through the resistance wire, Joule heating heats up the 
cantilevers and, like a bimetal, they bend down to the substrate.  By 
distributing many of these actuators over the surface of a material, the 
material surface can be endowed with transport functions, and a tiny 
carrier machine can be realized.  

Research on bacterial flagella to find a model for micromachines in
living organisms is energetically being carried out here.  Flagella use
protein molecules as parts, and are referred to as nature's smallest
"molecular motors"; to a bacteria, they play the role of a screw.
Recently it was reported that experiments to freely control the
rotational speed of flagella were successful (Nihon Keizai Shimbun, 20
May 1991, p19).  This was built upon the discovery that the rotational
speed of the flagella of Salmonella bacteria, which were fixed in a
nutrient medium on the tip of a glass tube 1mu-m in diameter, was
proportional to the voltage that was applied between two electrodes set
up on the inside and outside of the tube.

In view of the importance seen of micromachine production technology,
Japan's New Energy Development Organization (NEDO) began a "Micromachine
Technology" as a new project, which began in 1991, as part of a large
MITI-AIST project (the Large Industrial Technology R&D System).  This is
a ten-year R&D project with about 25B Yen from MITI. As I have reported
previously, many Japanese companies are participating, and in Japan,
significant progress is anticipated in the field. While this report
focuses on Japanese activities, I should point out that there is a great
deal of similar work in progress in the West.  In fact I recently saw an
excellent demonstration of experiments that were conducted at IBM's
Japan Technical Research Lab, clearly indicating that Big Blue is
extremely interested in the topic.

----------------------------END OF REPORT-----------------------------