A Multifunctional Bioelectronic Device with Switchable Rigidity and Reconfigurable Shapes for Comprehensive Diagnosis

Abstract Soft bioelectronic devices have potential in medical applications, especially comprehensive diagnoses that rely on immovable equipment to acquire multiple physiological signals. Challenges for bioelectronic devices lie in the opposite modulus demand for multifunctional integration and biocompatibility, and shape compatibility for reducing implantation trauma and covering target tissue. Here, this work reports a multifunctional bioelectronic device endowed with switchable rigidity and reconfigurable shapes by a fast thermal response shape memory polymer substrate. The customizable substrate has a melting temperature around body temperature (≈38 °C) and an ≈100 times modulus drop (from ≈100 MPa to ≈700 kPa). The switchable rigidity realizes stacked layers fabrication in the rigid state and self‐adaptive contact in the soft state. Shape reconfiguration allows the device to be implanted through small incisions and recover in limited spaces to envelop biosurfaces. Multiple physical, biochemical, and electrophysiological signal sensing functions are integrated in the device, realized by temperature and pH electrodes with linear, stable, and fast responses and a low‐impedance potential electrode. For some epilepsy and pericardial effusion types that a single physiological parameter fails to distinguish, animal experiments demonstrate efficiency in their comprehensive diagnosis with electrocorticogram assisted by brain temperature and electrocardiogram assisted by pericardial fluid pH, respectively.