The Charles Stark Draper Laboratory, Inc.

Eric M Hildebrant

Marc Steven Weinberg

Paul A Ward

Brian T Cunningham

Anthony S Kourepenis

Lance C Niles

Steven T Cho

Ralph E Hopkins, Iii

Robert A Bousquet

Shida Iep Martinez

Harold Ralph Haley

A method for manufacturing a flexural plate wave sensor, the method including the steps of depositing an etch-stop layer over a substrate, depositing a membrane layer over said etch stop layer, depositing a piezoelectric layer over said membrane layer, forming a comb pattern with drive teeth which span across an entire length of the piezoelectric layer on said piezoelectric layer, etching a cavity through the substrate, the cavity having substantially parallel interior walls, and removing a portion of the etch stop layer between the cavity and the membrane layer to expose a portion of the membrane layer.

Flexural plate wave sensor

A flexural plate wave sensor including a flexural plate having a length and a width and a comb pattern over the flexural plate with drive teeth disposed across the entire length of the flexural plate to reduce the number of eigenmodes excited in the plate and thereby simplifying the operation and design of the flexure plate wave sensor.

A fully integrated charge amplifier with DC stabilization includes a first amplifier having an input terminal and an output terminal, a first capacitor coupled between the input terminal and the output terminal of the first amplifier, a transimpedance amplifier having an input terminal coupled to the output terminal of the first amplifier and an output terminal, and an impedance device coupled between the input terminal of the first amplifier and the output terminal of the second amplifier. The impedance device has a resistance of at least 1 M&#x3a9;.

Charge amplifier device having fully integrated DC stabilization

Trenches which reduce or eliminate force and sensitivity associated with proof mass motion normal to the substrate as a result of voltage transients is disclosed. The trenches provide increased separation between interleaved comb electrodes and the substrate, and thereby also reduce the comb lift to drive ratio. The trenches are typically formed directly below the interleaved comb electrodes, but may also be formed below other suspended portions. Trench depth is from 6-10 microns and provides a comb electrode to substrate separation of approximately 8.5-12.5 microns.

Trenches to reduce charging effects and to control out-of-plane

A micromechanical tuning fork gyroscope having two center electrodes is disclosed. The two center electrodes are excited with bias potentials of opposite polarity. The oppositely biased center electrodes provide electrical symmetry across the gyroscope and thereby reduce charge transients and sensitivity to vertical translation. Currents injected directly into the proof masses are equal and opposite and thus cancel. Motor lift forces acting on the proof masses and interleaved electrodes are equal, and hence the proof masses move in pure translation, thereby reducing in-phase bias. Further, any pure translation normal to the plane of the gyroscope does effect sense axis output signals.

Growing community of inventors

Watertown, MA, United States of America

Eric M Hildebrant