SILK FIBROIN ELECTRONICS: MATERIAL TECHNOLOGY FOR SOFT AND CONFORMAL ELECTRICAL SENSOR IMPLANTS

Abstract

Naturally occurring biomaterials provide a coercive platform to reinterpret and redefine standard inorganic polymeric fabrication processes in a sustainable and green manner. Silk proteins represent a unique family of biopolymers due to their novel structure and soft material properties. We make use of these properties and other soft technology routes to enable a wide range of soft and conformal implantable electrical sensors on sustainable silk substrates, the first of its kind, that provide a conformal lamination on the curvilinear tissue geometries. First, we report the material technology for realizing silk electrode sensors to the neural tissues (the cortex and the peripheral nerves). In the latter part of the thesis, we realize for the first time, three-dimensional flexible vertical electrical interconnects that enable electrical connectivity across metallized silk layers and subsequently employ them in the fabrication of soft silk circuit prototypes. The thesis explores the conjunction of technological and practical attributes of silk fibroin targeting implantable device technologies, to successfully establish naturally occurring silk fibroin as a credible alternative to the current inorganic polymeric substrates, and further spur the redirection of widely-used stiff inorganic plastic needs to organic and softer options.