# US 7,408,283 B2 · Micromachined ultrasonic transducer cells having compliant support structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,408,283 B2 - Document ID: US7408283B2 - Status: Granted - Kind: B2 - Application number: 11/348,984 - Filed: 2006-02-07 - Published: 2006-06-15 - Granted: 2008-08-05 - Earliest claimed: 2003-12-29 - Assignees: General Electric Company - Inventors: Lowell Scott Smith; Douglas G. Wildes - Web page: https://patentgrep.com/patent/US7408283B2 ## CPC - B06B 1/0292: {Electrostatic transducers, e.g. electret-type} - H02N 1/006: {of the gap-closing type (H02N1/004 takes precedence)} - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) - H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR ## Abstract A micromachined ultrasonic transducer array comprising a multiplicity of cMUT cells built on a substrate. Each cMUT cell comprises a compliant support structure built on the substrate, a membrane supported over a cavity by the compliant support structure, a first electrode supported by the membrane, and a second electrode that forms a capacitor with the first electrode, the cavity being disposed between the first and second electrodes. The compliant support structure uncouples the non-membrane outer surface of each cMUT cell from the supporting substrate. ## Claims ### Claim 1 A cMUT cell array comprising a plurality of groups of cMUT cells, wherein each group comprises a compliant support structure, a first membrane supported over a first cavity by said compliant support structure, a first electrode supported by said first membrane, a second electrode that forms a capacitor with said first electrode, said first cavity being disposed between said first and second electrodes, a second membrane supported over a second cavity by said compliant support structure, a third electrode supported by said second membrane and hard-wired to said first electrode, and a fourth electrode hard-wired to said second electrode and arranged to form a capacitor with said third electrode, said second cavity being disposed between said third and fourth electrodes, and a portion of said compliant support structure being disposed between said first and second cavities, wherein the first or second electrode of a first group of the plurality of groups is not hard wired to the first or second electrode of a second group of the plurality of groups. ### Claim 2 (depends on 1) The cMUT cell array as recited in claim 1, wherein at least one group of the plurality of groups further comprising first and second pedestals, said second electrode being supported by said first pedestal and said fourth electrode being supported by said second pedestal. ### Claim 3 (depends on 1) The cMUT cell array as recited in claim 1, wherein said compliant support structure in cross section resembles a cantilevered beam. ### Claim 4 (depends on 3) The cMUT cell array as recited in claim 3, wherein the at least one group of the plurality of groups further comprising a fifth electrode formed on a surface of said compliant support structure, said fifth electrode being hard-wired to at least one of said first and third electrodes. ### Claim 5 (depends on 3) The cMUT cell array as recited in claim 3, wherein the at least one group of the plurality of groups further comprising a fifth electrode formed on a surface of said compliant support structure, said fifth electrode being hard-wired to at least one of said second and fourth electrodes. ### Claim 6 (depends on 1) The cMUT cell array as recited in claim 1, wherein said compliant support structure in cross section resembles a double cantilevered beam. ### Claim 7 (depends on 6) The cMUT cell array as recited in claim 6, wherein the at least one group of the plurality of groups further comprising a fifth electrode formed on a surface of said compliant support structure, said fifth electrode being hard-wired to at least one of said first and third electrodes. ### Claim 8 (depends on 6) The cMUT cell array as recited in claim 6, wherein the at least one group of the plurality of groups further comprising a fifth electrode formed on a surface of said compliant support structure, said fifth electrode being hard-wired to at least one of said second and fourth electrodes. ### Claim 9 (depends on 1) The cMUT cell array as recited in claim 1, wherein the compliance of said compliant support structure and the stiffness of each of said first and second membranes are selected so that each of said first and second membranes vibrates in a piston-like manner. ### Claim 10 (depends on 1) The cMUT cell array of claim 1, wherein the compliant structure reduces the coupling between the sound field and the cMUT transducer substrate. ### Claim 11 (depends on 1) The cMUT cell array of claim 1, wherein the compliant support structure comprises a coil-spring like structure. ### Claim 12 (depends on 1) The cMUT cell array of claim 1, wherein the first and second membranes are contiguous. ### Claim 13 (depends on 1) The cMUT cell array of claim 1, further comprises at least one parallel-plate capacitor incorporated in the compliant support structure. ### Claim 14 (depends on 1) The cMUT cell array of claim 1, wherein the compliant support structures produce substantially uniform displacement of the membranes. ### Claim 15 A cMUT cell array comprising a compliant support structure, a first membrane supported over a first cavity by said compliant support structure, a first electrode supported by said first membrane, a second electrode that forms a capacitor with said first electrode, said first cavity being disposed between said first and second electrodes, a second membrane supported over a second cavity by said compliant support structure, a third electrode supported by said second membrane and hard-wired to said first electrode, and a fourth electrode hard-wired to said second electrode and arranged to form a capacitor with said third electrode, said second cavity being disposed between said third and fourth electrodes, and a portion of said compliant support structure being disposed between said first and second cavities and having a cross section that resembles a double cantilevered beam, wherein the double cantilevered beam comprises a first ring-shaped wall built on a substrate, a first ring-shaped plate supported along one periphery by the first ring-shaped wall, a second ring-shaped wall built on the other periphery of the first ring-shaped plate, a second ring-shaped plate overlying the first ring-shaped plate and supported along one periphery by a wall therebetween, and a third ring-shaped wall built on the other periphery of the second ring-shaped plate. ### Claim 16 (depends on 15) The cMUT cell array of claim 15, further comprises a plurality of parallel-plate capacitors incorporated in the compliant support structure.