A multi-functional intracranial silk-based electronic interface with integrated temperature and pressure sensor

Abstract The acquisition of multiple brain activity signals, including electrophysiological signals, intracranial pressure (ICP), and intracranial temperature (ICT), is crucial for neuroscience research and the clinical treatment of brain disorders. Additionally, bioelectronic devices intended for in vivo operation require high standards of material safety. In this work, we report a multifunctional monolithic bioelectronic device based on oriented crystallization silk fibroin. The pre-stretched and fixed silk fibroin material exhibits remarkable in vivo stability enhancements. Using Micro Electromechanical System (MEMS) technology, units for the electrophysiological signal, ICP, and ICT collection are efficiently integrated into silk fibroin substrate. This integration is further complemented by an efficient backend connection to construct a system capable of multiple signal acquisitions. Through efficient connection, this multifunctional signal acquisition system can be used for simultaneous neural signal recording and miniaturized high-precision measurements of ICP (pressure coefficient of 48.5 Ω/kPa) and ICT (temperature coefficient of 0.39%). After implantation into the mouse cranium, the device is capable of efficiently synchronizing the acquisition of intracranial electrophysiological signals, intracranial pressure (ICP), and intracranial temperature (ICT) within two days. This class of bioelectronic devices based on silk fibroin effectively expands the efficient application of silk fibroin-based biomaterials.