A Synthetic Tympanic Membrane for Middle Ear Acoustic Sensor Tests of a Fully Implantable Cochlear Prosthesis

A physical model of human Tympanic Membrane (TM), based on PDMS, as an easily accessible test platform for acoustic transducers was designed and fabricated. • A primitive ear canal simulator (TM holder) design was done using COMSOL FEA. • Vibration behavior of TM was tested with a Scanning Laser Doppler Vibrometer (SLDV). • Effect of an attached mass on the membrane was performed utilizing 32 mg and 57 mg accelerometers. • The model reproduced the basic vibrational characteristics of a human TMThe authors acknowledge European Research Council (ERC) for the financial support through FLAMENCO Project (Project No: 682756)

Fabrication and Feasibility of Through Silicon Via for 3D MEMS Resonator Integration

In this study, development of a wafer level, void free TSV fabrication process flow and feasibility study of TSV integration to MEMS piezoelectric resonator devices have been presented. TSV structures with 100 mu m diameter and 350 mu m depth were copper filled with via sealing and bottom-up electroplating process which is a two-step technique. Four-point Kelvin measurements showed 0.8 m Omega TSV resistance on fabricated TSVs. Furthermore, TSV frames were epoxy bonded to MEMS acoustic transducers, which showed 90% to the resonator signal from the TSV

Thin Film PZT Acoustic Sensor for Fully Implantable Cochlear Implants

This paper presents design and fabrication of a MEMS-based thin film piezoelectric transducer to be placed on an eardrum for fully-implantable cochlear implant (FICI) applications. Resonating at a specific frequency within the hearing band, the transducer senses eardrum vibration and generates the required voltage output for the stimulating circuitry. Moreover, high sensitivity of the sensor, 391.9 mV/Pa @900 Hz, decreases the required power for neural stimulation. The transducer provides highest voltage output in the literature (200 mVpp @100 dB SPL) to our knowledge. A multi-frequency piezoelectric sensor, covering the daily acoustic band, is designed based on the test results and validated through FEA. The implemented system provides mechanical filtering, and mimics the natural operation of the cochlea. Herewith, the proposed sensor overcomes the challenges in FICI operations and demonstrates proof-of-concept for next generation FICIs