The long-term reliability of pre-charged CMUTs for the powering of deep implanted devices

Conference paper (2021)

Authors

M. Saccher Electronic Components, Technology and Materials - EEMCS
S. Kawasaki Electronic Components, Technology and Materials - EEMCS
R. Dekker Philips Research
Research Group
Electronic Components, Technology and Materials (EEMCS) (TU Delft)
Copyright: © 2021 M. Saccher, S. Kawasaki, R. Dekker
DOI
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https://doi.org/10.1109/IUS52206.2021.9593683
Ultrasound power transfer Pre-charged CMUT Capacitive micromachined ultrasound transducers Zero-bias transducers Accelerated lifetime test
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Published Date

2021

Language

English

Reuse Rights

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Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Microelectronics

Research Group

Electronic Components, Technology and Materials

Abstract

Recently, focused ultrasound has been proposed to power deeply implanted medical devices. Almost exclusively, lead zirconate titanate (PZT) transducers are used to convert acoustic energy into electrical energy. Unfortunately, these lead containing devices cannot be hermetically encapsulated since that would block the ultrasound. We propose the use of biocompatible Capacitive Micromachined Ultrasonic Transducer (CMUT) elements to replace traditional PZT transducers. In addition, to eliminate the external bias voltage, we introduced a charge trapping Al2O3 layer inside the CMUT to create a built-in bias voltage. These devices can be pre-charged and used as a receiver for US power. In this work, the viability of charged CMUTs to power deep implants was explored by investigating the effect of the charging parameters and by performing Accelerated Lifetime Tests (ALT). The estimated lifetime at body temperature ranges between 2.5 to 3.5 years at body temperature, which significantly depends on the charging parameters.