From Lithographically Patternable to Genetically Patternable Electronic Materials for Miniaturized, Scalable, and Soft Implantable Bioelectronics to Interface with Nervous and Cardiac Systems

Soft implantable bioelectronics, capable of maintaining an intimate, chronically stable tissue interface to provide single-cell spatial resolution, millisecond temporal resolution, and cell-type-specific interrogation and intervention, are important to biological research and clinical application. Despite remarkable advancements in recent years, the establishment of miniaturized, scalable, and soft bioelectronic interfaces to a large number of cells three-dimensionally (3D) distributed across cardiac and neural tissues in freely behaving animals and human subjects remains a challenge. In this Review, we discuss recent progress in studies and designs of lithographically and/or genetically patternable electronic materials to address these questions. First, we summarize the development of lithographically patternable electronic materials with proper electrical and mechanical properties, biocompatibility, and long-term stability for implantable bioelectronics. Then, we discuss examples of miniaturized, scalable, and soft implantable bioelectronics for brain and heart interfaces. Next, we introduce the most recent progress on the genetically targeted assembly and patterning of electrically functional polymeric materials on the neurons in intact 3D brains through the convergence of synthetic biology and polymer chemistry. Finally, the perspective of future development of implantable bioelectronics through the convergence of materials science, electrical engineering, and synthetic biology is discussed.