Bio-Inspired Inner-Ear Microphones via a Piezoelectric Substrate and Nanorods

通过压电基板和纳米棒的仿生内耳麦克风

• 批准号: 1030047
• 负责人: I-Yeu Shen
• 金额: $ 19.98万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1030047&HistoricalAwards=false
• 关键词: Bio; Inspired; Inner; Ear; Microphones

The research objective of this project is to develop an extra-sensitive microphone by mimicking hair cells in the cochlea. Human hearing is an extremely sensitive bio-sensing mechanism that has evolved for millions of years. The human ear consists of three parts: the outer ear, middle ear, and cochlea. The outer ear collects incoming sound waves to vibrate the eardrum. The middle ear transduces the vibration to pressure waves in the cochlea. Inside the cochlea, there are thousands of hair cells surrounded by fluid. Hair cells have nano-structured and patterned stereocilia swinging and deforming under tiny pressure fluctuations to sense the incoming sound. The pressure can be as low as 20 micro-Pa with a motion in the sub nm range in cochlea. As humans age, hair cells are gradually lost and hearing deteriorates. Exposure to noise can lead to further loss or damage of stereocilia. For nearly deaf patients (especially children), surgeons insert cochlear implants (CI) in the form of an electrode into cochlea to directly stimulate auditory neurons. The newest endeavor in CI research is to incorporate a microphone inside the cochlea along with the electrode. Such design has the advantage of no bulky external components, more natural hearing via auditory pathways, more versatile speech processing algorithms, and reduced surgical time and complexity. A major bottleneck is the unavailability of a tiny microphone with high enough sensitivity to fit into cochlea. Motivated by the needs for an intracochlear microphone in CI research, the PI plans to develop an extra-sensitive microphone by mimicking hair cells in the cochlea. The device consists of a piezoelectric substrate with electrodes and an array of patterned nanorods. When the pressure of the surrounding fluid fluctuates, each nanorod receives a drag force deforming the piezoelectric substrate to generate electric charge. The large number of nanorods significantly amplifies the generated charge enhancing the sensitivity to the pressure fluctuation. Three specific goals are set to achieve. First, to fabricate the bio-inspired microphone (BIM) using a silicon/PZT and a plastics/PZT substrate with nanorods, second, to conduct calibrated experiments to study the feasibility of the BIM, and third, to conduct an analytical study to understand how the pattern and dimensions of the nanorods affect the sensitivity of the BIM.It is anticipated that a good portion of the estimated 278 million people who have hearing disability could benefit from this research in hearing sensing. Hearing rehabilitation research will become progressively important, because US population is aging and life expectancy is increasing. The research will also broaden its impact via a well-designed international collaboration, recruitment of underrepresented and undergraduate students, curriculum revision, outreach, and publication of research results.

本计画的研究目的是借由模仿耳蜗毛细胞来发展一种超灵敏麦克风。 人类听觉是一种极其敏感的生物感知机制，已经进化了数百万年。人耳由三部分组成：外耳、中耳和耳蜗。 外耳收集传入的声波以振动鼓膜。 中耳将振动转换为耳蜗中的压力波。 在耳蜗内，有成千上万的毛细胞被液体包围。毛细胞具有纳米结构和图案化的静纤毛，在微小的压力波动下摆动和变形，以感知传入的声音。 压力可以低至20微帕，耳蜗中的运动在亚纳米范围内。 随着人类年龄的增长，毛细胞逐渐丢失，听力逐渐退化。暴露于噪声可导致静纤毛进一步丧失或损伤。对于近聋患者（特别是儿童），外科医生将电极形式的人工耳蜗植入物（CI）插入耳蜗，直接刺激听觉神经元。 人工耳蜗研究中最新的奋进是将麦克风与电极一起沿着在耳蜗内。 这种设计的优点是没有笨重的外部组件，通过听觉通路更自然的听觉，更通用的语音处理算法，以及减少手术时间和复杂性。一个主要的瓶颈是没有一个足够高灵敏度的微型麦克风来适应耳蜗。 受CI研究中对耳蜗内麦克风的需求的启发，PI计划通过模仿耳蜗中的毛细胞来开发一种超灵敏麦克风。 该器件由一个带有电极的压电衬底和一个图案化纳米棒阵列组成。当周围流体的压力波动时，每个纳米棒接收拖曳力，使压电基板变形以产生电荷。 大量的纳米棒显著地放大了所产生的电荷，增强了对压力波动的敏感性。 设定了三个具体目标。 首先，使用具有纳米棒的硅/PZT和塑料/PZT基板来制造生物启发麦克风（BIM），第二，进行校准实验以研究BIM的可行性，以及第三，进行分析研究，以了解纳米棒的图案和尺寸如何影响BIM的灵敏度。预计在估计的2.78亿听力正常的人中，残疾人可以从这项听力感知研究中受益。听力康复研究将变得越来越重要，因为美国人口正在老龄化，预期寿命正在增加。该研究还将通过精心设计的国际合作，招募代表性不足的学生和本科生，修订课程，推广和出版研究成果来扩大其影响。