Galvanic-Cell-Based Self-Powered Bioelectronic Devices

Bioelectronic devices hold significant promise for advancing biomedical technologies, addressing critical healthcare challenges, and improving the quality of human life. Conventional bioelectronic devices are typically powered by external, bulky batteries connected by extended electrical wires, which limit the compactness and miniaturization of bioelectronics, restrict patient mobility, and increase the risk of complications such as infections and device-related failures. This perspective discusses the emerging concept of galvanic-cell-based self-powered bioelectronic devices, in which galvanic electrodes serve directly as the tissue-contacting interfaces. We provide an overview of the principles and working mechanisms of biocompatible galvanic cells in galvanic devices for diverse biomedical applications, including electrical modulation, chemical and biochemical modulation, and hybrid electrical/(bio)chemical modulation, along with their control strategies: passive control and active control. Furthermore, we envision that the advancement of galvanic devices will represent a promising direction for biomedical applications, despite the presence of inherent challenges.