Piezoelectric performance of continuous beam and narrow supported beam arrays for artificial basilar membranes

Abstract

We report an experimental assessment of the electrical performance of two piezoelectric beam arrays for artificial basilar membranes (ABMs): a continuous beam array (CBA) and a narrow-supports beam array (NSBA). Both arrays consist of piezoelectric beams of sequentially varying lengths that mimic the frequency selectivity of mammalian cochleae. The narrow supports of the NSBA resulted in lateral deformation of the beams, whereas the CBA beams were flat. The displacement and piezoelectric output of each beam were measured at the resonance frequency of each beam using a scanning laser-Doppler vibrometer (SLDV). Both ABM prototypes showed mechanical frequency selectivity that depended on the beam length. The CBA generated a piezoelectric output in the range 6.6–23.2 μV and exhibited electrical frequency separability, whereas the NSBA failed to generate sufficient electrical potential due to the lateral deformation of the piezoelectric beams. The CBA was found to be more effective as an ABM, with potential for use in cochlear implants.