Swimmable Micro‐Battery for Targeted Power Delivery

Abstract The boom of microelectronic devices and their diverse applications has heightened the demand for innovative and effective energy supply strategies. The longevity of contemporary microelectronic devices predominantly depends on direct human intervention power supply methods, encompassing battery replacement or recharging. However, these methods may falter in specific scenarios, such as when facing liquid conditions in vivo. Here, a concept of swimmable micro‐batteries (MBs) for targeted power delivery is presented. This is achieved through the design of a flexible polydimethylsiloxane/Fe 3 O 4 soft‐magnetic substrate for actuation, polydimethylsiloxane/neodymium‐iron‐boron (NdFeB) hard‐magnetic tabs for precise targeting, and quasi‐solid‐state Zn//MnO 2 battery for power generation. These swimmable MBs exhibit an impressive areal capacity of 102.3 µAh cm‐2, remarkable waterproofing, adjustable output voltage or capacity, rapid response, and accurate remote magnetic field manipulation, enabling targeted power supply available. This novel swimmable MB design broadens the function of MBs and may open a new avenue for their future development.