Bioinspired Microstructured Pressure Sensor Based on a Janus Graphene Film for Monitoring Vital Signs and Cardiovascular Assessment

The rational structural design of materials is an efficient strategy for optimizing the sensing properties of pressure sensors for electronic skins. Here, inspired by the arches of the foot, a novel Janus graphene film (JGF) with concave-convex arch-shaped microstructures on both surfaces is presented. Then, a polymer-substrate-free pressure sensor with a wide sensing range, fast response time, and good stability is fabricated using a face-to-face assembly method. Its special microstructures can effectively hinder the full contact of two face-to-face JGF electrodes and lead to a tunable pressure-dependent contact area. Subtle pressure variations can be captured due to these special arch-shaped microstructures. Hence, the JGF-based pressure sensor could be used to monitor the vital signs of the human body such as human-body motion, breathing, and arterial pulse. Stable epidermal pulse wave signals are detected, and a series of indices are extracted to assess arterial stiffness and vascular aging. Thanks to its low-cost, simplified fabrication process, the pressure sensor exhibits great potential for monitoring health in real time and screening for arteriosclerotic disease.