Development of PZT Thin-Film Microactuators for Intracochlear Applications

PI：Shen提案：1159623背景：听力损失是老年人和在嘈杂环境中长时间工作的人的常见残疾。大多数听力损失患者由于耳蜗毛细胞功能障碍或丧失而患有感觉神经损伤。对于轻度至中度听力损失，传统助听器会放大传递到耳朵的声音。对于更严重的听力损失，人工耳蜗可以通过耳蜗中的电极直接电刺激听觉神经元。在这两个极端之间，有一组患者失去了相当大的高频听力，但保留了一些低频听力。 这些患者中的许多人使用助听器效果不佳，但不是人工耳蜗植入的候选人。 最近，有证据表明，对这一不断增长的患者群体来说，最有效的康复类型是在同一只耳朵中结合联合收割机电和声刺激（CEAS）。CEAS策略同时使用声放大（助听器）和电刺激（耳蜗植入）。结果表明，患者在噪声环境下有更好的单词识别。为了在单个设备中实现CEAS，刺激电极和声学致动器可能被集成并放置在耳蜗内。虽然耳蜗内电极是很好的研究，耳蜗内声学执行器是新颖的，并没有explored.Objectives目标：拟议的研究是开发铅锆钛氧化物（PZT）薄膜声学微致动器耳蜗内使用。有两个具体目标要实现。第一个目标是设计和制作一个微致动器探头，其尖端有一个PZT薄膜压电振膜作为声致动器。致动器的目标是提供200 nm的位移，带宽从15 Hz到3 kHz，尺寸小于0.8 mm x 0.8 mm。探头的尖端，用生物相容性材料密封，然后植入耳蜗。第二个目标是进行急性动物试验，以证明所提出的微致动器探头的可行性，通过测量豚鼠的听觉脑干反应。智力优点：拟议的研究有足够的智力优点。首先，拟议的研究是变革性的。这项研究的结果将使一类新的人工耳蜗植入物，整合电和声刺激在一个单一的设备。它将为目前的人工耳蜗技术开辟一个全新的方向。其次，拟议的研究极大地拓宽了该领域的知识。例如，拟议的研究有一个精心策划的动物研究来测试我们的假设并证明其可行性。 这将是第一个关于耳蜗内声学致动器的动物研究。第三，这项研究是翻译性的。以PZT薄膜技术为核心提出的研究方法形成了一种新的研究范式。它补充了传统的微机电系统（MEMS）技术，这些技术无法满足耳蜗内应用中遇到的挑战。 PZT薄膜技术还可以实现广泛的应用，如扫描内窥镜、DNA操作纳米定位器和生物流体粘度计。更广泛的影响：目前，据估计有2.78亿人患有听力残疾。 这些听力残疾患者的良好人群可能从所提出的耳蜗内致动器中受益。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。拟议的研究还将通过开发PZT薄膜微器件的新课程，招募代表性不足的本科生，通过专利和许可进行技术转让，工业和国际合作，推广和继续教育来扩大其影响。

PI: ShenProposal: 1159623Background: Hearing loss is a common disability in aging seniors and people who work long hours in noisy environments. The majority of persons with hearing loss have sensorineural impairments, due to dysfunction or loss of cochlear hair cells. For mild to moderate hearing loss, conventional hearing aids amplify sounds delivered to the ear. For more severe hearing loss, cochlear implants can directly stimulate auditory neurons electrically via an electrode in the cochlea. Between these two extremes, there is a group of patients who have lost considerable high-frequency hearing but have some preserved low-frequency hearing. Many of these patients do poorly with hearing aids but are not candidates for cochlear implants. Recently, there is evidence that the most effective type of rehabilitation for this growing group of patients is to combine electrical and acoustic stimulation (CEAS) in the same ear. The CEAS strategy uses acoustic amplification (hearing aid) and electrical stimulation (cochlear implant) simultaneously. Results show that patients have better word recognition under noisy environments. To enable CEAS in a single device, stimulating electrodes and acoustic actuators could potentially be integrated and placed inside cochlea. While Intra-cochlear electrodes are well studied, intra-cochlear acoustic actuators are novel and have not been explored.Objectives & Goals: The proposed research is to develop Lead-Zirconium-Titanium Oxide (PZT) thin-film acoustic micro-actuators for intra-cochlear use. There are two specific goals to achieve. The first goal is to design and fabricate a micro-actuator probe, whose tip has a PZT thin-film piezoelectric diaphragm serving as an acoustic actuator. The actuator aims to deliver 200-nm displacement for a bandwidth from 15 Hz to 3 kHz with a size less than 0.8 mm x 0.8 mm. The tip of the probe, sealed with a biocompatible material, is then implanted into the cochlea. The second goal is to conduct acute animal tests to demonstrate the feasibility of the proposed micro-actuator probe by measuring auditory brainstem responses in guinea pigs.Intellectual Merits: The proposed research has ample intellectual merits. First, the proposed research is transformational. Results of this research will enable a new class of cochlear implants that integrate electric and acoustic stimulation in a single device. It will open a completely new direction for the current cochlear implant technologies. Second, the proposed research tremendously broadens the knowledge of the field. For example, the proposed research has a well-planned animal study to test our hypothesis and demonstrate the feasibility. This will be the first animal study on intra-cochlear acoustic actuators. Third, this research is translational. The PZT thin-film technology at the core of the proposed research forms a new research paradigm. It complements traditional technology of micro-electric-mechanical-systems (MEMS), which are not able to meet the challenges encountered in intra-cochlear applications. The PZT thin-film technologies can also enable a wide range of applications, such as scanning endoscopes, nano-positioners for DNA manipulation, and viscosimeters for biofluids.Broader Impacts: Currently, it is estimated that 278 million people have hearing disability. A good population of these hearing-disabled patients can potentially benefit from the proposed intra-cochlear actuators. Hearing rehabilitation research will become progressively important, because US population is aging and life expectancy is increasing. The proposed research will also broaden its impact via development of new curriculum on PZT thin-film microdevices, recruitment of underrepresented and undergraduate students, technology transfer via patents and licensing, industrial and international collaboration, outreach, and continuing education.