Piezoelectrically actuated flextensional micromachined ultrasound transducers. II. Fabrication and experiments

This paper presents novel micromachined two-dimensional array piezoelectrically actuated flextensional transducers that can be used to generate sound in air or water. Micromachining techniques to fabricate these devices are also presented. Individual unimorph array elements consist of a thin piezoelectric annular disk and a thin, fully clamped, circular plate. We manufacture the transducer in two-dimensional arrays using planar silicon micromachining and demonstrate ultrasound transmission in air at 2.85 MHz with 0.15 /spl mu/m/V peak displacement. The devices have a range of operating resonance frequencies starting from 450 kHz to 4.5 MHz. Such an array could be combined with on-board driving and addressing circuitry for different applications.

[1]  Gökhan Perçin,et al.  Piezoelectrically actuated flextensional micromachined ultrasound transducers. , 2002, Ultrasonics.

[2]  Minoru Kurosawa,et al.  New Airborne Ultrasonic Transducer with High Output Sound Pressure Level , 1994 .

[3]  B. Khuri-Yakub,et al.  Piezoelectrically actuated flextensional micromachined ultrasound droplet ejectors , 2002, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[4]  J. S. Wood,et al.  Calculation and investigation of flexural-mode piezoelectric disk transducers on a passive substrate in reception and radiation , 1992 .

[5]  R. Nickell,et al.  Analysis of structural-acoustic interactions in metal-ceramic transducers , 1973 .

[6]  B. Khuri-Yakub,et al.  Micromachined 2-D array piezoelectrically actuated flextensional transducers , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[7]  N. Adelman,et al.  Flexural–extensional behavior of composite piezoelectric circular plates , 1980 .

[8]  Raphael Loewy,et al.  Axisymmetric Vibrations of Isotropic Composite Circular Plates , 1971 .

[9]  C. P. Germano.  Flexure Mode Piezoelectric Transducers , 1971 .

[10]  K.K. Li,et al.  Micromachined high frequency ferroelectric sonar transducers , 1997, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[11]  Thomas S. Lundgren,et al.  Controlled ink-jet printing and deposition of organic polymers and solid particles , 1998 .

[12]  Abdullah Atalar,et al.  Micromachined two-dimensional array piezoelectrically actuated transducers , 1998 .

[13]  Butrus T. Khuri-Yakub,et al.  Piezoelectrically actuated droplet ejector , 1997 .

[14]  B. Khuri-Yakub,et al.  Piezoelectrically actuated flextensional micromachined ultrasound transducers. I. Theory , 2002, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[15]  J. B. Greenberg,et al.  Flexural vibrations of certain full and annular composite orthotropic plates , 1979 .

[16]  A. M. Allaverdiev,et al.  Coupled flexural-shear oscillations of stepwise-layered piezoceramic disk transducers , 1987 .

[17]  Jonathan J. Bernstein,et al.  Micromachined ferroelectric transducers for acoustic imaging , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).