Plasma-assisted atomic layer deposition of alumina and Parylene-C bi-layer encaps

氧化铝和聚对二甲苯-C 双层封装的等离子体辅助原子层沉积

• 批准号: 8877517
• 负责人: Rajmohan Bhandari
• 金额: $ 33.41万
• 依托单位: BLACKROCK MICROSYSTEMS
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8877517
• 关键词: Address; Advanced Development; Aluminum Oxide; Architecture; Area; Benchmarking; Body Fluids; Brain; Ceramics; Characteristics; Charge; Chemicals; Chronic; Complex; Custom; Deposition; Development; Devices; Dimensions; Effectiveness; Electrodes; Electronics; Encapsulated; Environment; Extravasation; Failure; Foreign Bodies; Geometry; Gold; Health; Human; Implant; Injection of therapeutic agent; Ions; Lasers; Light; Longevity; Measures; Medical Device; Metals; Methods; Monitor; Neurosciences; Operative Surgical Procedures; Performance; Phase; Plasma; Polymers; Procedures; Process; Production; Property; Protocols documentation; RF coil; Research; Risk; Scheme; Semiconductors; Site; Small Business Innovation Research Grant; Sorting - Cell Movement; Staging; Structure; Surface; System; Techniques; Technology; Testing; Utah; Water; Wireless Technology; Work; atomic layer deposition; biomaterial compatibility; brain machine interface; combat; electric impedance; electrical property; follow-up; implantable device; implantation; improved; in vivo; manufacturing process; microsystems; nervous system disorder; neural stimulation; neuroprosthesis; next generation; novel; parylene; parylene C; relating to nervous system; response; success

DESCRIPTION (provided by applicant): A range of neurological diseases are now being researched or treated using fully implantable electronic systems to either record or modulate brain activity in humans. These implants are currently being protected using polymer coatings that envelop the implant and help keep body fluids away from the sensitive electronics. Brain implants with complex three-dimensional geometries, like the Utah Electrode Array (UEA) shown in the figure, provide a challenge for current encapsulation techniques. Parylene has been the gold standard for encapsulation of neural and biomedical implants in general due to its well-suited combination of biocompatibility, electrical properties and chemical inertness. However recording capabilities of long-term neural implants (>6 months) encapsulated with Parylene show signs of degradation. To combat this problem Blackrock Microsystems proposes a novel bi-layer encapsulation scheme that combines Plasma Assisted Atomic Layer Deposited (PA-ALD) alumina layer underneath the Parylene layer. This encapsulation scheme, novel to biomedical field, will retain all the advantages of Parylene while utilizing vastly superior dielecric properties of underlying ALD alumina layer to create a much longer lasting and more electrically stable biomedical implants. This bi-layer encapsulation scheme may be seamlessly incorporated into our existing fabrication process flow for our flagship product, the UEA. The bi-layer The UEA with integrated electronics encapsulation method will work on different surfaces (metal, semiconductor, polymer, ceramic) and on devices with integrated wireless components making it ideal for coating any complex medical device intended for long term implant. The project has 4 specific aims: Specific Aim 1: Optimize an ALD alumina/Parylene bi-layer encapsulation scheme and compare performance with Parylene-only encapsulation on test devices. Specific Aim 2: Develop etch methods to selectively expose active electrode sites on UEAs coated with optimized ALD alumina/Parylene bi-layer. Specific Aim 3: Evaluate charge injection/impedance characteristics of ALD alumina/Parylene bi-layer coated UEAs. Specific Aim 4: Comparison of in vivo performance of ALD alumina/Parylene bi-layer coated UEAs to Parylene-only coated UEAs. Our preliminary results with Parylene and alumina coated planar interdigitated electrode (IDE) test structures are very promising in support of the proposed work. We have shown that the bi-layer encapsulation yields more stable leakage current, and stable impedance (with <5% change) at 67 �C for about 5 months (approximately equivalent to 40 months at 37 �C). This superior performance of bi-layer encapsulation suggests its potential usefulness for chronic implants with complex surface geometries. At the end of the Phase I 'Lab to Marketplace' SBIR project, Blackrock expects to have developed protocols and standards to transform this research from its current early-stage lab setting into a commercial-grade manufacture process.

描述（由申请人提供）：目前正在使用完全植入式电子系统来研究或治疗一系列神经系统疾病，以记录或调节人类的大脑活动。这些植入物目前正在使用包裹植入物并帮助保持身体健康的聚合物涂层进行保护。具有复杂三维几何形状的脑植入物（如图所示的犹他电极阵列（UEA））对当前的金标准封装技术提出了挑战。由于其生物相容性、电特性和化学惰性的完美结合，通常用于神经和生物医学植入物的封装，但是用聚对二甲苯封装的长期神经植入物（> 6个月）的记录能力显示出退化的迹象。 Blackrock Microsystems 提出了一种新颖的双层封装方案，该方案将等离子体辅助原子层沉积 (PA-ALD) 氧化铝层结合在聚对二甲苯层下方。在生物医学领域，将保留聚对二甲苯的所有优点，同时利用底层 ALD 氧化铝层的极其优越的介电特性来创建更持久、电气更稳定的生物医学植入物。这种双层封装方案可以无缝地融入我们现有的制造工艺中。我们的旗舰产品 UEA 的双层 UEA 采用集成电子封装方法，适用于不同的表面（金属、半导体、聚合物、陶瓷）以及具有集成无线组件的设备。该项目有 4 个具体目标：具体目标 1：优化 ALD 氧化铝/聚对二甲苯双层封装方案，并在测试设备上与纯聚对二甲苯封装进行性能比较。蚀刻方法选择性地暴露涂有优化 ALD 氧化铝/聚对二甲苯双层的 UEA 上的活性电极位点 具体目标 3：评估电荷注入/阻抗特性。 ALD 氧化铝/聚对二甲苯双层涂层的 UEA。具体目标 4：ALD 氧化铝/聚对二甲苯双层涂层的 UEA 与仅聚对二甲苯涂层的 UEA 的体内性能比较。测试结构非常有希望支持所提出的工作，我们已经证明双层封装可产生更稳定的漏电流和稳定的电流。 67°C 下约 5 个月（约相当于 37°C 下 40 个月）阻抗（变化 <5%）。双层封装的这种卓越性能表明其对于具有复杂表面几何形状末端的慢性植入物具有潜在的用途。在第一阶段“实验室到市场”SBIR 项目中，Blackrock 预计将制定协议和标准，将这项研究从当前的早期实验室环境转变为商业级制造流程。