Design, Simulation, Fabrication, and Characterization of Low-Frequency CMARs Relying on Flexible and Bio-Compatible Electronics for Cis

The requirements for cochlear implants (CIs) vary over time and go beyond present device performance. In this work, capacitive micromachined acoustic receivers (CMARs) are adopted to promote low-frequency acoustic transducer development. Nowadays, half-implantable CIs are based on piezoelectric materials and face problems of large volume and low biocompatibility. CMARs can take advantage of electronic integration with bio-compatible materials to overcome obstructions, address issues of the self-heating effects, and fill narrow bandwidths from piezoelectric materials, which gives CMARs the potential to fulfill full-implantable CIs. CMARs are the improved product based on capacitive micromachined ultrasonic transducers (CMUTs). The commonplace micromachined materials for CMUTs limit the receivers' eigen frequencies of the first bulking mode shape in megahertz (MHz). Herein, flexible electronics with low Young's moduli, particularly, are regarded as film candidates for CMARs. Finite element modeling (FEM) is applied to demonstrate that CMARs with the polydimethylsiloxane (PDMS) film can achieve the human hearing range 12.44 kHz, which has been verified by characterization of fabricated CMARs, 13.11 kHz. These matched and profound results indicate that low-frequency CMARs may lead to the development of full-implantable CIs in medical and scientific research fields.