PhD Thesis Defense - Pengju Li (Bozhi Tian Group)

Multiscale Spatiotemporal Optoelectronic Biointerfaces

Bioelectricity regulates fundamental processes across biological scales, from intracellular structure assembly to organ-level electrical rhythms. Achieving precise spatiotemporal control of these signals is essential for both scientific discovery and therapeutic intervention. Yet, current bioelectronic interfaces often lack sufficient resolution, adaptability, and minimally invasive operation. This thesis presents the development of multiscale optoelectronic biointerfaces capable of modulating biological activity from subcellular structures and single cells to small-animal tissues, and large-animal organs. Key innovations include monolithic silicon architectures for high-precision modulation and self-organized gold–titania plasmonic metasurfaces enabling enhanced and tunable photocarrier profile, as well as advanced design to deep-tissue, fully-implanted and low-intensity photoelectroceuticals. We demonstrate translational applications for regulating cardiac rhythm and treating both obstructive and central sleep apnea. Complemented by a biohybrid sensing and therapeutic system, this work lays the foundation for minimally invasive optoelectronic implants that advance our understanding of bioelectricity and accelerate clinical translation