Abstract

Monitoring internal physiological signals is essential for effective medical care 1 , yet most current technologies rely on external measurements or imaging systems that cannot capture enough deep-tissue dynamics 2 , 3 , 4 , 5 , 6 . Implantable devices offer a solution, but conventional designs often require batteries or magnets 7 , 8 , 9 , 10 , 11 , which carry risks during removal, and existing biodegradable sensors based on passive inductor–capacitor circuits are limited by short readout distances and unstable communication issues 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 . Here we describe a soft, biodegradable, wireless sensing device that can monitor pressure, temperature and strain over long distances (up to 16 cm), maintaining accuracy across varying positions and angles. This is achieved through a ‘pole-moving sweeping’ readout system combined with a folded structure that integrates mechanical flexibility with electromagnetic function. In vivo tests in the abdominal cavity of horses reliably captured deep-tissue pressure and temperature, and ex vivo measurements demonstrated accurate strain monitoring without strict positional control. The long-distance and wide-angle readout of soft biodegradable implants holds translational promise for accessing deep-tissue physiological signals.