title: High frequency piezoelectric MEMS ultrasound transducers.
abstract: High-frequency ultrasound array transducers using piezoelectric thin films on larger structures are being developed for high-resolution imaging systems. The increase in resolution is achieved by a simultaneous increase in operating frequency (30 MHz to about 1 GHz) and close coupling of the electronic circuitry. Two different processing methods were explored to fabricate array transducers. In one implementation, a xylophone bar transducer was prototyped, using thin film PbZr(0.52)Ti(0.48)O(3) (PZT) as the active piezoelectric layer. In the other, the piezoelectric transducer was prepared by mist deposition of PZT films over electroplated Ni posts. Because the PZT films are excited through the film thickness, the drive voltages of these transducers are low, and close coupling of the electronic circuitry is possible. A complementary metal-oxidesemiconductor (CMOS) transceiver chip for a 16-element array was fabricated in 0.35-microm process technology. The ultrasound front-end chip contains beam-forming electronics, receiver circuitry, and analog-to-digital converters with 3-Kbyte on-chip buffer memory.
authors.affiliation: Materials Research Laboratory, Pennsylvania State University, University Park, PA, USA.
authors.forename: Ioanna G
authors.initials: IG
authors.lastname: Mina
authors.forename: Hyunsoo
authors.initials: H
authors.lastname: Kim
authors.forename: Insoo
authors.initials: I
authors.lastname: Kim
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Park
authors.forename: Kyusun
authors.initials: K
authors.lastname: Choi
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Jackson
authors.forename: Richard L
authors.initials: RL
authors.lastname: Tutwiler
authors.forename: Susan
authors.initials: S
authors.lastname: Trolier-McKinstry
mesh_terms: D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008839:Microelectrodes; D008904:Miniaturization; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods