Magnetically controllable battery-free multifunctional ingestible and versatile smart e-pill

Smart, compact, and battery-free sensing platforms are increasingly required for structural and health monitoring in hard-to-reach environments. Here, we demonstrate an IoT-enabled multimodal electronic capsule (e-Pill) that integrates flexible, tunable temperature and light sensors within a battery-free architecture. The developed e-Pill is among the smallest reported to date, with a diameter of 6 mm and a length of 20 mm, and can be magnetically actuated for precise navigation in structural and biological systems. Magnetic controllability enables guided motion, accurate positioning, and reliable data acquisition in confined or dynamic environments. The e-Pill detects abnormalities and defects through variations in temperature and light intensity, with real-time monitoring achieved using a customized IoT platform and smartphone interface. Designed for both ingestible and non-ingestible operation, the e-Pill is suitable for a wide range of biological and structural health monitoring applications. The ingestible e-Pill effectively tracks the release of drugs or chemical agents in complex environments. Experiments are conducted within a fish model to demonstrate the feasibility of the developed e-Pill for real-life biomedical applications.