Enabling flexible, wearable, and implantable electronics with radio frequency‐based wireless charging: Fundamentals, challenges, and emerging applications

Abstract Wireless charging delivers power wirelessly across an air gap to recharge electronic devices without requiring direct physical connections. The rapid advancements in wireless charging technologies and the emergence of commercial products have introduced an alternative to overcome the energy limitations of traditional portable, battery‐operated devices. This paper offers an in‐depth review of radio frequency (RF)‐based wireless charging, emphasizing its applications in flexible electronics. We begin with a comprehensive overview of wireless charging methods, followed by a detailed introduction to RF‐based charging principles. We then review the applications of RF‐based charging in wearable devices, biomedical systems, integrated flexible and stretchable electronics, and on‐body wireless data transmission. Wireless charging, RF, flexible electronic, wearable devices.