Untethered Electrical Stimulation Using Optoelectricity and Piezoelectricity for Tissue Regeneration

Electrical signals are increasingly recognized as important regulators of tissue development and regeneration, with outcomes linked to behaviors including proliferation, differentiation, cell migration, and more. However, conventional electrical stimulation commonly relies on electrodes, wires, and power sources to deliver bioelectrical signals, which complicates integration with both the body and the regenerating tissue in question. Untethered electrical stimulation using optoelectronic and piezoelectric platforms offers an alternative strategy by transducing remotely supplied energy directly at the tissue interface, reducing the need for external connections. In this review, we first discuss the bioelectrical mechanisms through which electrical stimuli may influence regenerative cellular behavior, before examining recent applications of these materials in neural and bone regeneration. Finally, we identify future directions of these technologies based on key limitations of the current research, including the need for adaptive stimulation, transient materials, improved safety, and scalable fabrication. Together, these advances may enable a new generation of regenerative technologies capable of providing localized, minimally invasive, and adaptable stimulation during tissue repair.