Selective excitation of microcantilever array using ultrasound radiation force.

Abstract

The symmetric and antisymmetric eigenstates of a coupled pair of 500 956 m length microcantilevers were excited using the ultrasound radiation force. The excitation was produced using the difference frequency between the two sidebands of a double sideband suppressed carrier AM (DSB‐SC‐AM) waveform centered on 500 kHz that was emitted by a pair of focused ultrasound transducers. A laser Doppler vibrometer measured the frequency response and deflection shapes of the cantilever pair. When the waveforms sent to the transducer resulted in radiation force from both transducers with the same phase, it excited the 10.00 kHz symmetric state of the cantilever array while suppressing the 10.17 kHz antisymmetric state. Similarly, when the radiation force from the two transducers was 180 degrees out of phase, it selectively excited the antisymmetric state while suppressing the symmetric state. This ability to selectively excite different vibrational eigenstates is a unique capability of this noncontact for modal excitation.