Kitsopoulos Panagiota, Grosh Karl
Department of Mechanical Engineering, University of Michigan, G. G. Brown Building, 2350 Hayward Street, Ann Arbor, Michigan 48109, USA.
Department of Biomedical Engineering, University of Michigan, Carl A. Gerstacker Building, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109, USA.
J Acoust Soc Am. 2025 Jun 1;157(6):4385-4396. doi: 10.1121/10.0036848.
Hearing aids and cochlear implants help patients treat their hearing loss, but have limitations impacting their use rates. Completely implantable auditory prostheses would expand the range of activities a prosthesis user could engage in and enable 24/7 use. However, the lack of a completely implantable microphone that is robust, lightweight, and low noise prevents the wide adoption of implantable devices. Current implantable sensors struggle to meet or exceed the performance necessary for this application. This work develops a discretized and exhaustive design optimization approach to identify multi-bandwidth transducers that meet the 20-phon noise floor over 100 Hz-8 kHz. The design procedure is based on an experimentally validated analytical model that simulates the response of miniature piezoelectric microelectromechanical systems (MEMS) accelerometers. A four-bandwidth accelerometer with constrained proof mass thicknesses is selected as the design that best balances area minimization with ease of manufacturability. The estimated MEMS die dimensions are 825 μm × 575 μm, which is a 23% MEMS die area reduction compared to the previously published dual-bandwidth sensor [A. E. Hake, P. Kitsopoulos, and K. Grosh, IEEE Sens. J., 23(13), 13957-13965 (2023)].
助听器和人工耳蜗有助于患者治疗听力损失，但存在局限性，影响了它们的使用率。完全可植入式听觉假体将扩大假体使用者可以参与的活动范围，并实现全天候使用。然而，缺乏坚固、轻便且低噪音的完全可植入式麦克风阻碍了可植入设备的广泛应用。目前的可植入传感器难以达到或超过该应用所需的性能。这项工作开发了一种离散化且详尽的设计优化方法，以识别在100 Hz至8 kHz范围内满足20方本底噪声的多带宽换能器。该设计过程基于一个经过实验验证的分析模型，该模型模拟了微型压电微机电系统（MEMS）加速度计的响应。选择了一种具有受限质量块厚度的四带宽加速度计作为最佳设计，它在最小化面积与易于制造之间实现了最佳平衡。估计的MEMS芯片尺寸为825μm×575μm，与之前发表的双带宽传感器相比，MEMS芯片面积减少了23%[A. E. Hake, P. Kitsopoulos, and K. Grosh, IEEE Sens. J., 23(13), 13957 - 13965 (2023)]。
