Graphene–Polymer Nanocomposite‐Based Redox‐Induced Electricity for Flexible Self‐Powered Strain Sensors

Graphene as a powerful inorganic material such as excellent conductivity and ideal mechanical strength has recently been extensively utilized to develop flexible strain sensors. However, graphene‐based strain sensors usually suffer from the deficiencies of stretchability, sensitivity, and sensing range, which can restrict their applications in wearable devices. Here, a novel strain sensor is designed by integrating graphene/ecoflex film and meandering zinc wire into the flexible base. The constructed strain sensor not only possesses high stretchability of up to 150% strain but can also self‐generates current signals from redox‐induced electricity, where the stable current and voltage signals of about 75 µA and 0.83 V can be obtained, respectively. Furthermore, the self‐powered sensor presents a broad and linear sensing range of 25% to 150% strains and a fast response time of less than 0.11 s. Attached on human body, the sensor has been utilized to realize the motion detection of knee joint.