A Proposal for a High-Sensitivity Optical MEMS Accelerometer With a Double-Mode Modulation System

AbstractThis paper describes a novel, semiautomated design methodology based on a genetic algorithm (GA) using freeform geometries for microelectromechanical systems (MEMS) devices. The proposed method can design MEMS devices comprising freeform geometries and optimize such MEMS devices to provide high sensitivity, large bandwidth, and large fabrication tolerances. The proposed method does not require much computation time or memory. The use of freeform geometries allows more degrees of freedom in the design process, improving the diversity and performance of MEMS devices. A MEMS accelerometer comprising a mechanical motion amplifier is presented to demonstrate the effectiveness of the design approach. Experimental results show an improvement in the product of sensitivity and bandwidth by 100% and a sensitivity improvement by 141% compared to the case of a device designed with conventional orthogonal shapes. Furthermore, excellent immunities to fabrication tolerance and parameter mismatch are achieved.

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MEMS, MOEMS and Optoelectronics

10.1115/imece2001/mems-23900 ◽

2001 ◽

Author(s):

Ken Gilleo

Keyword(s):

Space Shuttle ◽

New Technology ◽

Optical Systems ◽

Digital Micromirror Device ◽

Optical Mems ◽

Micro Electro Mechanical Systems ◽

Instant Message ◽

Mems Accelerometer ◽

All Optical

Abstract Traditional MEMS (Micro-Electro-Mechanical Systems) devices have been with us for decades. A micromechanical motion sensor connected to the airbag electronics in your vehicle is always ready to send the instant message that can save your life. Sensing an abrupt change in motion indicating a crash, the MEMS accelerometer sends the command to fire the airbag. Today, multiple-axis motion-monitoring chips are on the market, so sensitive, that they can measure subtle hand motions. The ADI 202 will be demonstrated as part of this presentation. MEMS sensors are in wide use today but much more advanced activator type products are gaining market recognition as this technology advances. MOEMS (MicroOptoElectroMechanical Systems), or optical MEMS, adds “light” or optics to the technology cluster to provide the most advanced nano-devices yet. Texas Instruments is a pioneer in the MOEMS field with their highly successful Digital Micromirror Device (DMD™) now used in the best digital projectors and in cinemas. The DMD has more moving parts than a Boeing 777 and the Space Shuttle combined. We will do a case study of the DMD technology and review three products including “Redtooth” fiberless optics wireless. Optoelectronics, an “old-new” technology, is now the centerpiece of advanced communications especially for long-haul communications. A single optical fiber replaces over 4-million copper wires because of the unimaginable bandwidth resulting from the million-times higher frequency of light and the ability to multiplex hundreds of signals over a single fiber using Wave Division Multiplexing (WDM). But Internet links must be switched back and forth between electronic and photonic media. The reason is that routers and switches depend on electronics while transmission utilizes photonics. Many believe that MOEMS-based switches will solve the multiple conversion bottleneck allowing all-optical systems to smoothly handle traffic. So while MEMS, MOEMS and OE are separate, they all come together in fields like telecom. This paper will highlight these technologies and show how they will merge in an incredible future.

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