Chen Yanfei, Kim Yun-Soung, Tillman Bryan W, Yeo Woon-Hong, Chun Youngjae
Department of Industrial Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
George W. Woodruff School of Mechanical Engineering, College of Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Materials (Basel). 2018 Mar 29;11(4):522. doi: 10.3390/ma11040522.
The rapid development of micro/nanofabrication technologies to engineer a variety of materials has enabled new types of bioelectronics for health monitoring and disease diagnostics. In this review, we summarize widely used electronic materials in recent low-profile implantable systems, including traditional metals and semiconductors, soft polymers, biodegradable metals, and organic materials. Silicon-based compounds have represented the traditional materials in medical devices, due to the fully established fabrication processes. Examples include miniaturized sensors for monitoring intraocular pressure and blood pressure, which are designed in an ultra-thin diaphragm to react with the applied pressure. These sensors are integrated into rigid circuits and multiple modules; this brings challenges regarding the fundamental material's property mismatch with the targeted human tissues, which are intrinsically soft. Therefore, many polymeric materials have been investigated for hybrid integration with well-characterized functional materials such as silicon membranes and metal interconnects, which enable soft implantable bioelectronics. The most recent trend in implantable systems uses transient materials that naturally dissolve in body fluid after a programmed lifetime. Such biodegradable metallic materials are advantageous in the design of electronics due to their proven electrical properties. Collectively, this review delivers the development history of materials in implantable devices, while introducing new bioelectronics based on bioresorbable materials with multiple functionalities.
微纳制造技术的快速发展使得人们能够制造出各种材料，从而催生了用于健康监测和疾病诊断的新型生物电子学。在这篇综述中，我们总结了近期低调可植入系统中广泛使用的电子材料，包括传统金属和半导体、软聚合物、可生物降解金属和有机材料。由于制造工艺已完全成熟，硅基化合物一直是医疗设备中的传统材料。例如，用于监测眼压和血压的微型传感器，其设计为超薄隔膜，以便与施加的压力发生反应。这些传感器被集成到刚性电路和多个模块中；这就带来了一个挑战，即基本材料的特性与目标人体组织（本质上是柔软的）不匹配。因此，人们研究了许多聚合物材料，用于与特性明确的功能材料（如硅膜和金属互连）进行混合集成，从而实现柔软的可植入生物电子学。可植入系统的最新趋势是使用在设定寿命后能自然溶解于体液的瞬态材料。这种可生物降解金属材料因其已被证实的电学性能，在电子学设计中具有优势。总的来说，这篇综述介绍了可植入设备中材料的发展历程，同时引入了基于具有多种功能的生物可吸收材料的新型生物电子学。
