US 12,459,003 B2
Ultrasonic transducer with stacked membranes
Paul Louis Maria Joseph Van Neer, Bergschenhoek (NL); Arno Willem Frederik Volker, Delft (NL); Gerwin Hermanus Gelinck, Valkenswaard (NL); Hylke Broer Akkerman, Rosmalen (NL); and Antonius Maria Bernardus Van Mol, Veldhoven (NL)
Assigned to Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO, 's-Gravenhage (NL)
Appl. No. 17/796,467
Filed by Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO, 's-Gravenhage (NL)
PCT Filed Feb. 2, 2021, PCT No. PCT/NL2021/050063
§ 371(c)(1), (2) Date Jul. 29, 2022,
PCT Pub. No. WO2021/158101, PCT Pub. Date Aug. 12, 2021.
Claims priority of application No. 20155216 (EP), filed on Feb. 3, 2020.
Prior Publication US 2023/0347381 A1, Nov. 2, 2023
Int. Cl. B06B 1/06 (2006.01); B06B 1/02 (2006.01)
CPC B06B 1/0611 (2013.01) [B06B 1/0215 (2013.01); B06B 1/0292 (2013.01); B06B 2201/20 (2013.01); B06B 2201/51 (2013.01); B06B 2201/55 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An ultrasonic transducer comprising:
a stack of at least two membranes attached to a substrate, wherein a first membrane and a second membrane of the at least two membranes are separated by a spacing there between, wherein the substrate surrounds the stack in a plane of the membranes; wherein the first membrane in the stack is parallel and facing the second membrane in the stack, wherein the first membrane and the second membrane are configured to vibrate at an ultrasonic frequency for transceiving ultrasonic waves, and wherein the first membrane and the second membrane each comprise a set of electrodes;
an electric circuit coupled to the set of electrodes with a controller configured to apply a first electric signal to a first electrode on the first membrane, and a different, second electric signal to a second electrode on the second membrane; wherein the first electric signal and the second electric signal are configured to apply a varying voltage between the first electrode and the second electrode during a respective vibration cycle of the membranes at the ultrasonic frequency; and wherein the first electrode on the first membrane is configured to interact with the second electrode on the second membrane by a varying electrostatic force during the respective vibration cycle depending on the varying voltage.