Title :
Micromachined Bulk Wave Acoustic Bandgap Devices
Author :
Olsson, Roy H., III ; Fleming, James G. ; El-Kady, Ihab F. ; Tuck, Melanie R. ; McCormick, Frederick B.
Author_Institution :
Sandia Nat. Lab., Albuquerque
Abstract :
A MEMS bulk wave acoustic bandgap has been designed and experimentally verified. The acoustic bandgaps are realized by including tungsten (W) scatterers in a SiO2 matrix. Wide frequency ranges where acoustic waves are forbidden to exist are formed due to the large density and acoustic impedance mismatch between W and SiO2. The acoustic bandgap structures are fabricated in a 7-mask process that features integrated aluminum nitride piezoelectric couplers. Acoustic bandgaps in a square lattice have been measured at 33 and 67 MHz with up to 35 dB of acoustic rejection and bandwidths exceeding 35% of the midgap.
Keywords :
bulk acoustic wave devices; micromechanical devices; piezoelectric devices; 7-mask process; MEMS bulk wave acoustic bandgap device; aluminum nitride piezoelectric coupler; fabrication technology; Acoustic devices; Acoustic scattering; Acoustic waves; Aluminum nitride; Couplers; Frequency; Impedance; Micromechanical devices; Photonic band gap; Tungsten; acoustic bandgap; acoustic crystal; aluminum nitride; phononic bandgap; phononic crystal;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems Conference, 2007. TRANSDUCERS 2007. International
Conference_Location :
Lyon
Print_ISBN :
1-4244-0842-3
Electronic_ISBN :
1-4244-0842-3
DOI :
10.1109/SENSOR.2007.4300132
