Worldwide R&D

Creative Designs for Microfabricated InformationProcessing and Medical Equipment
Masayuki Nakao
Professor,Engineering Research Institute, Faculty of Engineering, the University of Tokyo
Forming teams with professional designers and researchersof different fields in our laboratory, we ascertain functions
required in new devices and design microfabrication methods
for achieving those functions. Primarily, we are targeting fields
of information-processing and medical equipment by applying
many microfabrication techniques aimed at concocting new andcreative prototypes through repeated attempts and failures. In
these attempts, we develop an upper level concept based on adesigner's thinking process diagram and accumulate the results
as explicit knowledge, as defined in knowledge management.
When failures occur, we take up the situation at the occurrenceof the failure in order to get further use from the design attempt
as a case study on design failure. In short, by conducting
creative designing alone without imitating others, we can obtainthe most thorough research data without regard for success andfailure of the research.
In our research laboratory, we use so-called micromachine
manufacturing technologies without thinking of them as newtechniques, but rather as potential manufacturing methods as
obvious as cutting, casting, and other age-old technologies.
Micromachine technology has been present in Japan for morethan a decade and now enjoys widespread use. However, in thefuture I believe we must bring micromachine experts together
with experts of conventional mechanical engineering. People
desire products, not manufacturing techniques. I do not believe
the public cares what methods are used to create a product,
providing the required functions are achieved.
Here, I introduce methods of assembly and reproduction
only attempted by a few researchers in shaping processes.
The right diagram in Fig. 1 shows a micro-house that has
appeared many times on television and in newspaper articles.
While we have accumulated many other achievements in ourlaboratory besides this and have made painstaking efforts todescribe them to media personnel, the media still focuses onlyon the micro-house. Perhaps this is because the micro-housecan be readily understood just by looking at it and does not
require a complex technical explanation. However, it took fouryears to be able to develop this micro-house. As shown in theleft diagram, the micro-house is assembled and bonded under ascanning electron microscope using an electrostatic tool having

50µm

50µm

Fig.2 Micro-insemination employing rotation (right)

Tool
Nucleus

DNA

Tool

50µm

DNA

50µm

Fig.3 Handling DNA

50µm

50µm

Fig.4 Microchannel press-molded on a glass substrate

a diameter of 15µm and a semiconductor laser with an output of
1.6 W that are moved with a total of 20 degrees-of-freedom.
While, in an engineering sense, the micro-house can becreated if one has a mind to, such construction is not a
profitable enterprise. Since the microassembly of cell phonecomponents and magnetic heads has less than one cent of addedvalue, it is obviously more advantageous to have the work
performed by cheap laborers with 20/20 vision.
However, there exists some microassembly work that has anadded value of more than one-hundred dollars, such as work inbiotechnology including the micro-insemination of sperm,
electrical stimulation of specific cells, and isolated cultivation ofspecific chromosomes. The right diagram in Fig. 2 shows anoperation of introducing sperm into the cell membrane of anovum while the tool is rotated. The left diagram shows the same
operation performed by simply pushing in with the tool. Here,the ovum deforms much more than that in the right diagram,risking injury to the DNA. Fig. 3 illustrates an operation of
extracting DNA from a chromosome, then isolating, stretching,and cutting the DNA strands. While DNA strands 2 nm indiameter are flowed, fluorescent molecules are attached toFig.1 Manufacturing a micro-house3

pressed only on the core portion of the triangular groove twice
using a piezo element. Hence, it is possible to accurately
reproduce a micro-shape, such as a groove, up to about a 30-nmwidth.
However, the problem is attempting to reproduce a
workpiece several millimeters square without bending theworkpiece. Wavefront aberrations are a problem in optics. For
example, a 20-nm flatness and parallelism is necessary in a 2mm square diffraction grating. In this case, it is not enoughsimply to create the micro-shape of the die, but also it isnecessary to analyze physical phenomena that occur during thereproduction and to control cooling and the distribution ofpressure and deformation to prevent residual stress.
In addition to assembly and reproduction, other general
methods of shape formation include removal, addition, anddeformation. I believe that methods of shape formation, such as"growth" known in reproductive medicine will emerge fromnanotechnology in the future. At that time, we will be able toproduce anything by preparing the proper DNA father andculture medium mother. Perhaps this is what has conventional
designers paralyzed with fear.

SEM imageAFM image

Fig.5 Triangular grooves formed through polystyrene
injection molding

specific parts of the DNA, then a DNA strand is handled briefly
relying on the fluorescent light. This type of microassembly canbe achieved with the proper micro-tools.
Next, I will describe reproduction assembly. Fig. 4 shows an
L-letter patterned groove having a width of 20µm and a depth of2µm that is reproduced by press-molding on glass. Aftermasking a carbide die with resist, the die is formed by blasting
and reproduced to the glass under a temperature of 530;. Fig.
5 shows triangular grooves formed at a pitch of 1µm by injection
molding on plastic. To obtain an accurate reproduction, we

MMC Activities

The 7th International Micromachine Symposium
enterprises and organizations that had participated in the "MicromachineTechnology Project" (completed in March 2001) - part of the Industrial
Science and Technology Frontier Program by MITI- each presented theresults of their team's research results, as a summary of the project.
The scheduling and content of the presentations in thissymposium were regarded highly by participants, as showed by thecomments for the questionnaires submitted after the of the entire
program.
The schedule for the next symposium is shown below.

The 7th International Micromachine Symposium was held at theScience Museum in Kitanomaru Park, Tokyo, on October 31 andNovember 1, 2001.
On the first day, the symposium program began with an opening
address by Mr. Toshiro Shimoyama, Chairman of the Micromachine
Center, followed by guest speeches by Mr. Iwao Okamoto, DirectorGeneral of the Manufacturing Industries Bureau, METI, and Mr. Keiichi
Aoyagi, Executive Director of NEDO with words of expectation tomicromachine technology and encouragement for the efforts toconcerned persons.
The symposium was very successful, despite the participants fromoverseas were greatly reduced as a result of the September 11 terrorist
attacks in New York. The venue packed with participants to almost full
capacity on both days,total participants for the two-day program
numbered 380, including 267 registered participants, presenters, andmembers of the press.
On the first day, Prof. Fumio Kodama of The University of Tokyo
Research Center for Advanced Economic Engineering gave a special
lecture entitled "Micromachine and Business Model," exploring thetopic which is currently of greatest interest to those within theindustry.
Other program items on the first day included sessions entitled"The Path to Micromachine Industries in the 21st Century," "Overseas
Activities," "Innovative R&D," and "Micromachine in the Last Decadeand Future Outlook". A total of 16 invited lecturers, including 4 fromabroad, made presentations during these sessions.
The second day of the program began with a speech by Mr. Yukihiro
Hata, Director- General of the Industrial Technology Development
Department of NEDO. After this, researchers representing 23

The 8th International Micromachine Symposium
Period: November 14 (Thu), 2002
P l a c e : Science Hall, the Science Museum in
Kitanomaru Park, Tokyo

View of Symposium Hall4