ABSTRACT The ability to interrogate and control bioelectrical activity with high spatial and temporal precision is central to understanding and manipulating complex biological systems. While conventional bioelectronic platforms excel at extracellular recording and stimulation of 2D monolayered cells, they remain fundamentally limited in interfacing with cells within 3D tissue constructs and organoids. Recent advances in optoelectronic materials offer a path toward leadless, genetically independent, and spatially precise biointerfaces capable of overcoming these barriers. This perspective highlights recent advances in optoelectronic biointerfaces, spanning from macroscale flexible silicon and organic devices to nanoscale free‐standing nanomaterials, with a particular focus on silicon‐based optoelectronics. We discuss the photoelectrochemical (Faradaic and capacitive) phenomenon at the biointerface, and how device geometry, doping configuration, and dimensionality critically determine the balance between capacitive, Faradaic, and photothermal effects. Special emphasis is placed on intracellular silicon nanowires, which uniquely combine spontaneous cellular internalization with subcellular optoelectronic actuation. Finally, we outline key challenges and propose material and device‐engineering strategies to advance nanoscale Electrical Modulation, Intracellular, and Leadless, optoelectronics toward practical 3D bioelectronic and biomedical applications.
Assaf et al. (Wed,) studied this question.