High-performance self-powered integrated system of pressure sensor and supercapacitor based on Cu@Cu₂O/graphitic...

With the rapid development of human-machine technology, self-powered pressure sensor integrated systems have been extensively studied. However, there are only a few reports on such multifunctional devices using a single active material. In this work, we report a flexible integrated system, which consists of flexible pressure sensors and supercapacitors. Both of the devices were fabricated based on layered porous Cu@Cu₂O/graphitic carbon (Cu@Cu₂O/GC) composites, which were obtained by a one-step simple polymer heat treatment method. Due to the discontinuous conductive paths and effective stress concentration relief in the composite, the pressure sensor shows a high sensitivity of 90 kPa^-1 in a wide working range of 0-150 kPa, a fast response time of 90 ms, and a detection limit of 2.4 Pa. Moreover, the layered porous structure Cu@Cu₂O/GC can not only maintain the integrity of the electrode material, but also promote the diffusion of electrons, enabling super capacitors to obtain excellent electrochemical performance. The specific capacitance of the super capacitor is 17.8 mF cm^-2. More importantly, the flexible self-powered integrated system could be directly attached to the human body to detect human motions, showing its great potential application in wearable devices.