Hermetic Nanowire Interconnects for Neural Prostheses

描述（由申请人提供）：植入式微电子设备越来越多地被接受为各种疾病的治疗选择，包括：耳聋，运动障碍和尿失禁。这些装置由微电子元件组成，封装在一个生物兼容的保护包内。被称为互联的电导体穿过包裹，刺激和记录神经元。像人工耳蜗这样的现代设备有22个相互连接。相比之下，正在开发的视觉和皮质假体可能需要数百个电极，每个电极都有自己的相互连接，以满足患者的需求。目前最先进的植入式电子互连不能满足这些要求。可植入微电子互连技术的发展受到合适制造工艺的限制。我们建议开发一种密封的、生物兼容的微电子封装，该封装将基于电沉积铂纳米线阵列的互连衬底嵌入纳米多孔氧化铝中。我们的初步结果表明，纳米线互连阵列（NIA）是密封的。这种密封性是一种独特的性质，也是将沉积限制在纳米长度尺度的直接结果。相反，电沉积不能完全填充微米级孔隙。因此，这种纳米技术是一种将电子设备与神经组织连接起来的新方法。该研究计划主要关注该技术的两个最具挑战性的方面：1)坚固且可重复的NIA制造；2)将NIA连接到密封封装中。除了这两项活动外，还将进行初始系统测试和生物相容性评估。氦气泄漏测试将用于评估密封性。将使用标准钎焊方法将NIA连接到密封包中。加速浸渍测试将用于预测封装寿命。最初的生物相容性研究将使用标准和定制测试进行。

DESCRIPTION (provided by applicant): Implantable microelectronic devices are becoming increasingly accepted as treatment options for a variety of disorders including: deafness, movement disorders, and urinary incontinence. These devices consist of microelectronic components housed inside of a biocompatible protective package. Electrical conductors called interconnects, penetrate through the package to allow stimulation and recording of neurons. Present-day devices like the cochlear implant have 22 interconnects. In contrast, visual and cortical prostheses under development may require hundreds of electrodes, each with its own interconnect, to meet the needs of patients. State of the art implantable electronic interconnects cannot meet these requirements. Advancement of interconnect technology for implantable microelectronics is limited by the availability of suitable fabrication processes. We propose to develop a hermetic, biocompatible microelectronics package that incorporates an interconnect substrate based on arrays of electrodeposited platinum nanowires embedded in nanoporous aluminum oxide. Our preliminary results suggest that the nanowire interconnect array (NIA) is hermetic. This hermeticity is a unique property and direct result of restricting the deposition to nanometer length scales. In contrast, electrodeposition does not fill micron scale pores completely. Thus, this nanotechnology is a novel method for interfacing electronics with neural tissue. The research plan places primary focus on the two most challenging aspects of the technology: 1) robust and repeatable NIA fabrication and 2) joining the NIA to a hermetic package. In addition to these two activities, initial system test and biocompatibility assessments will be performed. Helium leak testing will be used to assess hermeticity. Standard brazing methods will be used to join the NIA to a hermetic package. Accelerated soak testing will be used to predict package lifetime. Initial biocompatibility studies will be done using standard and custom tests. Neurological disorders pose difficult medical problems, since damaged neurons do not heal well if at all. Neurosensory diseases of the eye, like age-related macular degeneration (AMD) and retinitis pigmentosa (RP), are leading causes of retinal blindness. RP has an incidence of 1/4000 live births and AMD blinds 200,000 eyes each year. Paralysis afflicts 100,000s each year through stroke or spinal cord injury, among other causes. Disorders such as Parkinson's disease, essential tremor, epilepsy, and chronic pain are other neurological diseases that have a significant and negative impact on public health. Neural prostheses have the potential to treat these disorders through electrical stimulation of nerves. The proposed research plan would advance a key technology in support of future neural prosthetic systems.