Design and Modelling of MEMS Resonators for an Artificial Basilar Membrane

Abstract

The human cochlea is undeniably one of the most amazing organs in the body. One of its most intriguing features is its unique capability to convert sound waves into electrical nerve impulses. Humans can generally perceive frequencies between 20 Hz and 20 kHz with their auditory systems. Several studies have been conducted on building an artificial basilar membrane for the human cochlea (cochlear biomodel). It is possible to mimic the active behavior of the basilar membrane using micro-electromechanical systems (MEMSs). This paper proposes an array of MEMS bridge beams that are mechanically sensitive to the perceived audible frequency. They were designed to operate within the audible frequency range of bridge beams with 450 µm thickness and varying lengths between 200 µm and 2000 µm. As for the materials for the bridge beam structures, molybdenum (Mo), platinum (Pt), chromium (Cr) and gold (Au) have been considered. For the cochlear biomodel, gold has proven to be the best material, closely mimicking the basilar membrane, based on finite-element (FE) and lumped-element (LE) models.

Keywords

• MEMS
• cochlear biomodel
• finite element (FE)
• lumped element (LE)