Artificial hair cells inspired by active hair bundle motility

Abstract

Hair cells are specialized sensory cells found in the auditory and vestibular systems of many vertebrates. Many of these cells display an active hair bundle motility that amplifies the hair cell’s response to small stimuli, increases frequency sensitivity, and produces an amplitude compression that allows the cell to transduce a large range of input amplitudes. These features are important in an animal’s ability to detect and understand complex stimuli in its environment. The hair bundle’s nonlinear amplification results from combination of a nonlinear stiffness produced by opening and closing ion channels and an adaptation motor that brings the hair bundle close to a dynamic instability. This article presents the models and designs for a bio-inspired, artificial hair cell inspired by active hair bundle motility. These sensors are based on cantilevered beams with a nonlinear stiffness and a piezoelectric actuator to mimic the adaptation motor. Artificial hair cells can serve as bio-inspired microphones hydrophones, accelerometers, or other dynamic sensors. By mimicking hair bundle motility, these sensors could detect smaller stimuli, have enhanced frequency resolution, and transduce a wider range of input levels compared to traditional sensors.