Dynamic Characterization of Biomimetic Artificial Hair Cells

Abstract

The research presented in this paper investigates the relationship between fluid flow characteristics in an artificial cochlear environment and artificial hair cell sensor response. First, a lipid bilayer-based hair cell sensor is created to model the inner hair cells of the human cochlea. The artificial cochlear environment is then fabricated to recreate the pulsating fluid flow around the artificial inner hair cell stereocilia. Mechanical excitation creates sinusoidal fluid flows in the artificial cochlear environment at a range of frequencies determined by the response of the hair cell sensor in air. For excitation frequencies at and below 40 Hz, the response of the hair cell sensor is approximately equal to the control case having no bilayer. At these low frequencies, bilayer dynamics do not appear to lead to current generation. At frequencies at and above 70 Hz, and in the absence of an externally applied DC offset across the bilayer, the hair cell sensors featuring a bilayer generate up to double the RMS current. Therefore, for excitation frequencies at and above 70 Hz, bilayer dynamics play a significant role in hair cell sensor response. Further testing of the hair cell sensor shows that applying a DC offset across the bilayer increases the peak-to-peak sensor output by up to a factor of 80.