Monitoring internal physiological signals is essential for effective medical care1, yet most current technologies rely on external measurements or imaging systems that cannot capture enough deep-tissue dynamics2–6. Implantable devices offer a solution, but conventional designs often require batteries or magnets7–11, which carry risks during removal, and existing biodegradable sensors based on passive inductor–capacitor circuits are limited by short readout distances and unstable communication issues12–19. 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.
