Lamb wave resonator-based torque sensor
AssigneeTexas Instruments Incorporated
InventorsJeronimo Segovia Fernandez, Peter Smeys
Life of this patent
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Abstract
A torque sensor chip including a semiconductor substrate, an acoustic reflector formed on the semiconductor substrate, and first and second Lamb wave resonators (LWRs). The first LWR is formed on a side of the acoustic reflector opposite the semiconductor substrate. The first LWR is at a first angle with respect to an axis of the IC. The second LWR also is formed on the side of the acoustic reflector opposite the semiconductor substrate. The second LWR is at a second angle, different than the first angle, with respect to the axis of the IC.
Claims23
A torque sensor chip, comprising:
- a semiconductor substrate;
- an acoustic reflector formed on the semiconductor substrate;
- a first Lamb wave resonator (LWR) formed on a surface of the acoustic reflector opposite the semiconductor substrate, the first LWR oriented at a first angle with respect to an axis of the torque sensor chip;
- a second LWR formed on the surface of the acoustic reflector opposite the semiconductor substrate, the second LWR oriented at a second angle, different than the first angle, with respect to the axis of the torque sensor chip;
- and
- a third LWR formed on the surface of the acoustic reflector opposite the semiconductor substrate, the third LWR oriented approximately parallel to the axis of the torque sensor chip.
A device, comprising:
- a semiconductor substrate having a cavity formed therein;
- and
- a Lamb wave resonator (LWR) including a metal layer formed over the cavity to completely cover the cavity.
A torque sensor device, comprising:
- a shaft;
- a semiconductor substrate formed on an outer surface of the shaft;
- a Bragg acoustic reflector formed on the semiconductor substrate;
- a first Lamb wave resonator (LWR) formed on a surface of the Bragg acoustic reflector opposite the semiconductor substrate, the first LWR oriented at a first angle with respect to an axis of the shaft, the first LWR resonator including a first interdigitated electrode and a first pair of side acoustic reflectors on opposite sides of the first interdigitated electrode;
- a second LWR formed on the surface of the Bragg acoustic reflector opposite the semiconductor substrate, the second LWR oriented at a second angle, different than the first angle, with respect to the axis of the shaft, the second LWR resonator including a second interdigitated electrode and a second pair of side acoustic reflectors on opposite sides of the second interdigitated electrode;
- a third LWR formed on the surface of the Bragg reflector opposite the semiconductor substrate, the third LWR oriented approximately parallel to the axis of the shaft and a circuit configured to determine torque based on signals from the first, second, and third LWRs.
Dependencies are inferred from the claim text.