MEMS Rotary Engine Power System Electromagnetic Valve Eri

MEMS Rotary Engine Power System / Electro-magnetic Valve Eri Takahashi, Albert Pisano APP 90 © 2006 University of California Prepublication Data March 2006

Long Term Goal • Part of an effort to create an innovative MEMS Smart Plate involving various sensors, a MEMS fuel delivery system, and a silicon carbide wear surface • Integrating MEMS valve into fuel delivery system • Developing a novel planar-design MEMS Electro-magnetic actuator that creates micro Newton force, several hundred displacement in harsh environments • Development of a metering normally-off valve © 2006 University of California Prepublication Data March 2006

Valve System Overview • The principle is based on a variable reluctance stepper motor. • Ni. Fe will be electroplated on an armature © 2006 University of California Prepublication Data March 2006 body.

Hole-in-a-Wall Valve • Planar structure - Can be easily integrated into planar micro-fluidic system • Current design exhibit 3. 9 x 1015 Ns/m 5 fluidic resistance and good fluidicsresistance ratio greater than 3500 with water J. A Frank and A. P. Pisano, Proceedings of 2004 Solid-State Sensor & Actuator Workshop, Hilton Head, South Carolina © 2006 University of California Prepublication Data March 2006

Actuator Design Crab-leg suspensions Flux guides Ni. Fe in Si cradle © 2006 University of California Prepublication Data March 2006

Process Flow © 2006 University of California Prepublication Data March 2006

Process Challenges Electroplating Ni. Fe on SOI wafer • How to form a seed layer? • How to connect electrodes? DRIE with presence of embedded Ni. Fe • What to use for masking? • Any effect on sidewall features etc. ? © 2006 University of California Prepublication Data March 2006