from July 31 to August 1, 2008 in Tokyo/Japan

Japanese-German Micro/Nano Business Forum, IVAM Area, booth W1-272

The Fraunhofer IPMS carries out customer specific developments in fields of microelectronic and micro systems technology in Dresden, serving as a business partner that supports the transition of innovative ideas into new products. The Fraunhofer IPMS develops and fabricates modern CMOS technology products in its own clean room facilities, up to small pilot series production. With modern equipment and about 150 scientists, the range of projects and expertise covers sensor and actuator systems, microscanner, spatial light modulators, lifetronics and organic materials and systems.

At the Micromachining/MEMS show the Fraunhofer IPMS presents:

1. 1D and 2D Micro Scanning Mirrors

The resonantly driven Micro Scanning Mirror is designed for periodical deflection of light. The actuator chip is fabricated with a CMOS compatible micromachining technology. A circular respectively elliptic silicon plate serves as mirror plate and is suspended by two torsional springs. In the case of the 2D Scanner a gimbal mounting of the mirror plate is used. The oscillation of the plate is excited electrostatically. As all the mechanical parts are made of single crystal silicon the devices show a very high robustness and long-term stability. A demonstrator with a large optical scan range of 120° optically will be shown at the booth.

2. Translational micro mirror for optical path length modulation

Optical metrology systems like Fourier Transform Spectrometers or confocal microscopes require fast modulation of the optical path length to shorten measurement times. Conventional solutions with complex driving mechanics for the deflectable mirrors show high sensitivity against vibrations and shock. As a result they often are suitable for laboratory operation, only. Application of translational mirrors for optical path length modulation allows to overcome this disadvantage. In addition to high vibration and shock insensitivity, the advantage of high frequency operation and potential low fabrication cost for medium and high volumes enables the development of robust, fast and highly miniaturized metrology systems for industrial applications. Fabrication of the translational mirrors is done with a CMOS compatible MEMS-SOI technology. High reflectivity (app. 95 %) in the near and mid infrared range is achieved by an aluminization. The translational micro mirrors are optimized for medium and high frequency optical path length modulation. Typical applications are:

• Fourier-Transform (FT)-IRSpectrometry
• Confocal Microscopy
• Focal point variation

The oscillation of both, the 1D and 2D micro scanning mirror and the translational micro mirror, will be shown under stroboscopical light at our booth.

»The tiny dimensions of the mirrors enable totally new application fields as the integration of mirror based laser projection modules into mobile phones, miniaturized spectrometer or scanning photon microscopes«, explaines Dr. Harald Schenk, Fraunhofer IPMS' deputy director.

Our co-exhibitor, the CTR AG from Villach, Austria, presents spectrometers based on the micro scanning mirrors:

3. MOEMS Scanning Grating Spectrometer for the NIR

CTR's Grating Spectrometer operates according to the Czerny-Turner monochromator principle. Classical instruments typically employ a large grating. Instead, a micro scanning reflector – developed by IPMS – equipped with a reflective diffraction grating is utilised here. This innovative scanning grating technology is the key to compact low-cost spectrometers. The technology has been licensed and successfully launched by HiperScan.

4. FT-IR spectrometer for your pocket

Presently, spectrometric production process control requires sampling, followed by spectroscopic laboratory analysis. This is not only laborious and expensive, but also effects a significant time-lag until the results become available.

CTR is currently working on a solution to this problem in form of a cigarette packet-sized robust low-cost Fourier-Transform-Infrared (FT-IR) spectrometer. This development also uses one of the Fraunhofer IPMS's optical MEMS elements. Here, a minute translational micro-mirror, moving up to 1.000 times per second, allows for rapid analysis giving precise results. This measuring system is unique and already worldwide patented.

»With the opportunities of microsystem, spectrometers can become considerably smaller, faster, more reliable and, perhaps most importantly, more cost-effective.” Andreas Kenda, CTR project leader.