The 9th International Micromachine / Nanotech Symposium

Turning MEMS ideas into MEMS products
Stephen D. Senturia, Professor Emeritus, Massachusetts Institute of Technology, U.S.A.
Today I would like to talk about MEMS, on how to think the MEMS.
In July 2003, I had a lecture on "Turning MEMS ideas into
MEMS products" at the conference of "Transducers 03'" which
held in Boston, U.S.A. and Professor Fujita, who is here today,
was participating in my lecture. After that I was asked byProfessor Fujita to have a lecture on the same theme in Tokyo.
This is why we are meet here today. And I feel happy to have alecture here for you. The contents have modified to make much
more interesting. The items in my talk are MEMS's viewpoint in
the future and review in the past and I would like to talk on"Turning MEMS ideas into MEMS products" in the last.

building objects from the bottom up, with molecular manipulation andself-assembly. Nanometer-sized objects are being built for research
uses. Such devices inherently must include quantum effects in theirdescription. Given this shift, the MEMS practitioner has a choice:either go into "nanotechnology" (and many are doing that), or get
into an area that does not depend on basic-research funding, namely,products. The problem, of course, is that building products is difficult.

MEMS vs. MEMS-Enabled Products: An Example
It is useful to distinguish between two types of MEMS-basedproduct. In the first category, referred to as a "MEMS product",
the MEMS chip, with or without its primary package, is theproduct. Electronics may be integrated into the chip, as in theMotorola pressure sensor and the Analog Devices accelerometer.
The second category, referred to as a "MEMS-enabled" productincludes not only the MEMS chip and its package but also
ancillary components, external electronics, possibly embedded
software or firmware, and an overall product package. Bothcategories of product require test, calibration, documentation,and some kind of quality-management system (ISO orequivalent). The Polychromix Dynamic Channel Orchestrator
provides a good example of a MEMS-enabled product. The coretechnology is the polychromator, an electrically programmablediffraction grating with up to several thousand parallel mirror
elements suspended above a substrate, each one of which can be
actuated to change its height above the substrate. This creates
an aperiodic programmable diffraction engine capable of creating
synthetic spectra. While this technology was originally developed
for chemical sensing applications using optical spectroscopy, it is
now being applied to optical telecommunications byPolychromix. The product operates over the telecommunications
C-band (wavelengths near 1.55 microns), controlling the power
in 100 channels spaced 50 GHz apart over a 40dB dynamic range
under program control.

Let's review the MEMS in the past
The conference of Transducers was initiated in 1981, thenthere was no name of the abbreviation "MEMS" and the field ofresearch and development initially called solid-state sensors andactuators, which over time, morphed into Micro Electro
Mechanical Systems MEMS or Microsystems. The state of theMEMS field in the early 1980's, I can divide such three groups as
basic research, engineering science and product development.
There was much work in basic research on materials, sensing
methods, actuation methods and phenomena on a micron scale.
There was even more work on the engineering science of building
practical devices, with emphasis on materials and process
technology, integration methodologies, and system design. At
that time there were only a few microfabricated devices such aspressure sensor, gas sensor and ion sensor on the market.
However there were no journals devoted to MEMS, no regularconferences, and limited access to design and fabrication
infrastructure. The impact is sufficient that there are now
multiple journals devoted to MEMS and a variety of technicalmeetings. Individual disciplines that have a MEMS component are
now holding their own meetings, and it is now possible to go to ameeting involving MEMS or microsensors almost every week ofthe year. There are newsletters and trade magazines devoted tothe microworld, and a growing infrastructure of fabrication
vendors and equipment suppliers. Whereas only a few of thesewere on the market in the early 1980's, sensors for acceleration,
flow, and angular rate as well as a variety of optical MEMS andmicrofluidic and bioMEMS devices are now commerciallyavailable. And there are products - many products.

Conclusion
I have explored some of the challenges facing real-world
MEMS products, with emphasis on the higher-value-added
MEMS-enabled products. Even with these many difficulties, there
is enormous vitality and creativity in the MEMS community, andwith appropriate attention to the many risks and challenges
ahead, it will be possible to build, and successfully sell, new
MEMS-based products to a welcoming world. As a conclusion,ideas for MEMS have been already fulfilled and the developmentof MEMS technology has been become ready in every relating
fields. Moreover infrastructures to fabricate commercial products
such as foundry services, and CAD tools have been completed.
What the next step for MEMS is only to make products.

Trends for the Future
Looking forward from today, several trends are clear. The first isthat both the emphasis and the funding for basic research are shifting
into "nanotechnology," whatever that means. To some, it means
simply making smaller versions of what is already familiar in the"micro" world. But to most, it is a completely different subject,4