Giant Magnetoelastic Effect Enabled Stretchable Sensor for Self-Powered Biomonitoring

Interfacing with the human body, wearable and implantable bioelectronics are a compelling platform technology for healthcare monitoring and medical therapeutics. However, clinical adoption of these devices is largely shadowed by their weakness in humidity resistance, stretchability, durability, and biocompatibility. In this work, we report a self-powered waterproof biomechanical sensor with stretchability up to 440% using the giant magnetoelastic effect in a soft polymer system. By manipulating the magnetic dipole alignment, the sensor achieved a particularly broad sensing range from 3.5 Pa to 2000 kPa, with a response time of ∼3 ms. To validate the excellent performance of the magnetoelastic sensor in biomonitoring, both ex vivo porcine heart testing and in vivo rat model testing were performed for cardiovascular monitoring and heart disease diagnosis. With the obtained sensing data, we have successfully detected ventricular arrhythmia and ventricular fibrillation in the Sprague-Dawley rat model. Holding a collection of compelling features, including minimal hysteresis, ultrawide sensing range, waterproofness, and biocompatibility, the magnetoelastic sensor represents a unique platform technology for self-powered biomonitoring in both wearable and implantable manners.