1. Silicon Micro-Seismometer Feasibility A study by a team at Imperial College, UK, in supported by Kinemetrics Inc. I. Standley (Kinemetrics Inc.) Dr. W.T. Pike T. Semple et Al. (Optical and Semiconductor Devices Group, Department of Electrical and Electronic Engineering, Imperial College London, UK)

2. LATERAL SILICON SUSPENSION We have successfully created lateral resonant structures using DRIE etching in silicon which demonstrate high MTQ products under vacuum levels of <0.00001 Torr. The structures shown have a width of the order of 30μm and a depth of 525 μm. The “die” size is of the order of 2cm x 2cm These structures have been evaluated in an SEM under different pressure ranges and the “Q” measured, by the decay time of the mechanical oscillations.

3. Structures Vibrating in an SEM

4. Q Derived from SEM Measurements

5. MTQ of Silicon SeismometerStructureunder vacuum10Hz, 0.25g, & Q=40,000MTQ=1kg.sP<0.001 Torr

6. Future Work • Produce a silicon structure with integrated electro-magnetic actuator coil and displacement transducer at atmospheric pressure. Performance target is <1nano-g level from 100 seconds to 10Hz. • Evaluate possibility of a vacuum sealed device.