Evaluation of micro-epidermal actuators on flexible substrate for noninvasive, pediatric-friendly conductive hearing aid

总结 婴儿期和幼儿期的听力损失对语言和言语有不利影响 发展听力损失必须尽早识别和纠正，以避免终身后果。 小儿听力障碍的一种主要类型是传导性的，其中耳中的听觉通路是 阻塞或损坏，阻止声音正确传导到内耳。临时导电 听力损失（CHL），包括中耳炎和鼓膜穿孔，是通过药物治疗或 小手术解剖条件，如耳道闭锁，耳道狭窄和听骨畸形，导致 永久性的CHL，更难解决。普遍的做法要求外科手术，以纠正 助听器的使用方法是将助听器植入颅骨以绕过耳朵中的阻塞物。但这些 手术是侵入性的并且对新生儿和婴儿提出了挑战。由于风险，FDA指南 防止5岁以下儿童接受骨锚式助听器，这是成人的标准设备。 这项研究的长期目标是找到新的策略，非侵入性地将声音转移到内部 耳和地址儿童患者的CHL。核心假设是声音可以被转移到 通过皮肤-骨骼途径，使用软助听器对内耳进行治疗。该项目的创新之处在于将芯片级、 微机械传感器在柔性基板上实现微表皮致动器（MEA）， 产生与皮肤直接接触的声音，以真正的非侵入性方式振动骨骼并绕过CHL， 方式我们提出的援助将产生120分贝声压级的低质量，灵活的电子产品， 通过牢固地粘在婴儿的皮肤上显示出希望。这将消除所需的侵入性程序的需要 用于矫正手术和听觉骨整合植入物（AOI）以及风险和不适 与现有辅助设备中的机械致动器和刚性部件相关联。 本申请的目的是评估柔性基板对声耦合的功效， 助听器的选配方法有哪些？为此，我们确定了三个主要目标， 这个项目在目标1中，将评估和表征表皮和MEA之间的声耦合。 假设是柔性基底将减少与皮肤的声学失配并改善与皮肤的声学匹配。 声音耦合到耳朵里。与面部和身体运动相关的噪声以及摩擦噪声是 其特征在于目标2。假设柔软、适形、轻质MEA将随着面部和 身体运动，减少整体噪音。皮肤和MEA之间的粘合强度将在 目标3.由于尺寸小（1.5 cm × 2.5 cm × 300 µm）、质量轻（120 mg）和弹性模量低， 基质与表皮的结合力为1- 2kPa，成功实施 这些目标将确定与适合儿童的传导助听器相关的重要特征。

SUMMARY Hearing loss during infancy and early childhood has detrimental effects on language and speech development. Hearing loss must be identified and corrected as early as possible to avoid life-long consequences. One major type of pediatric hearing impairment is conductive, in which the auditory pathway in the ear is obstructed or damaged, preventing sounds from properly conducting to the inner ear. Temporary conductive hearing loss (CHL), including otitis media and tympanic membrane perforation, is addressed by medication or a minor surgery. Anatomical conditions such as aural atresia, canal stenosis and ossicular malformation result in permanent CHL and are more difficult to address. Prevalent practice calls for surgical procedures to correct the damage in the pathway or implant hearing aids into the skull to bypass the obstruction in the ear. However, these procedures are invasive and present challenges for newborns and infants. Because of the risks, FDA guidelines prevent children younger than 5 from receiving bone-anchored hearing aids that are standard devices for adults. The long-term goal of this research is to find new strategies to non-invasively transfer sounds into the inner ear and address CHL in pediatric patients. The central hypothesis is that the sounds can be transferred into the inner ear via the skin-bone route with soft hearing aids. The innovation in this project is to integrate chip-scale, ultrathin, micromechanical transducers on flexible substrates to achieve micro-epidermal actuators (MEAs), generating sounds in direct contact with the skin to vibrate the bone and bypass the CHL in a truly non-invasive manner. Our proposed aid will generate 120 dB SPL with ultrathin, low mass, flexible electronics, which have showed promise by robustly sticking to infants' skin. This will eliminate the need for invasive procedures required for corrective surgeries and auditory osseointegrated implants (AOI) as well as the risks and discomfort associated with mechanical actuators and rigid components in the existing aids. The objective of this application is to evaluate the efficacy of the flexible substrate on acoustic coupling, adhesion strength and motion-related noises in soft hearing aids. To that end, we defined three major aims for this project. In aim 1 the acoustic coupling between the epidermis and MEAs will be evaluated and characterized. The hypothesis is that the flexible substrate will reduce the acoustic mismatch with the skin and improve the acoustic coupling into the ear. The noises associated with facial and body motion as well as rubbing noises are characterized in aim 2. The hypothesis is that the soft, conformal, lightweight MEAs will move with facial and body motion, reducing overall noises. The adhesive strength between the skin and MEAs will be evaluated in aim 3. Because of the small size (1.5 cm × 2.5 cm × 300 µm), low mass (120 milligram), and low elastic modulus, the substrates gently bond to the epidermis with adhesion strength 1-2 kPa. The successful implementation of these aims will identify the important features tied to pediatric-friendly conductive hearing aids.