US 12,440,868 B2
Frequency-tunable ultrasonic device
Cyril Meynier, Tours (FR); and Dominique Gross, Tours (FR)
Assigned to VERMON SA, Tours (FR)
Appl. No. 17/636,673
Filed by VERMON SA, Tours (FR)
PCT Filed Aug. 18, 2020, PCT No. PCT/IB2020/000715
§ 371(c)(1), (2) Date Feb. 18, 2022,
PCT Pub. No. WO2021/033030, PCT Pub. Date Feb. 25, 2021.
Claims priority of provisional application 62/889,623, filed on Aug. 21, 2019.
Prior Publication US 2022/0314274 A1, Oct. 6, 2022
Int. Cl. B06B 1/02 (2006.01); B06B 1/06 (2006.01)
CPC B06B 1/0292 (2013.01) [B06B 1/06 (2013.01); B06B 1/0269 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An ultrasonic device, comprising an ultrasonic transducer comprising:
a membrane suspended above a cavity arranged on the upper surface side of a substrate;
a piezoelectric layer attached to a surface of the membrane;
a first electrode arranged on the lower surface side of the cavity; and
a second electrode arranged on the upper surface side of the cavity, in contact with the piezoelectric layer,
the device further comprising a control circuit connected to the first electrode and the second electrode and capable of simultaneously applying a first control voltage on the first electrode, and a second control voltage different from the first voltage on the second electrode,
wherein the control circuit is configured to, during a phase of emission of an ultrasound wave, apply a DC bias voltage on the first electrode, and apply an AC excitation voltage on the second electrode, and
wherein the control circuit is configured to, during a phase of reception of an ultrasound wave, apply a DC bias voltage on the first electrode, and read an AC voltage generated on the second electrode under the effect of the received ultrasound wave.