A High-Resolution Self-powered Flexible Pressure Sensor Matrix Based on ZnO Nanowires

Flexible pressure sensor matrix, which can perceive the external mechanical stimuli with high spatial resolution, is the essential component for the electronic skin (E-skin) and is also able to be applied in various areas such as health monitoring and disease diagnosis. However, the design and fabrication of high-resolution pressure sensors with a high linearity in medium pressure range (10 kPa-100 kPa) at no power consumption is seldom reported. Here, we fabricate a self-powered pressure sensor matrix based on wurtzite structured ZnO nanowires (NWs) grown by hydrothermal method. The geometry and density of ZnO NWs were analyzed using a finite element method (FEM) to optimize the sensing performance. The matrix with an area of 25 mm2 consists of 25 sensors with the dimension of each unit being 500 µm * 500 µm (density of 100/cm2). Each sensor can be accessed independently and shows a linear response for the pressure ranging from 15 kPa to 50 kPa. The proposed self-powered pressure sensor matrix in this study shows a great potential in the application of wearable devices.