Fast-Response and Broad-Detection-Range Flexible Capacitive Pressure Sensor Based on Origami-Structured Barium Titanate Nanoparticles/Graphene/Silicone Rubber Nanocomposites

Flexible pressure sensors are becoming increasingly significant in the realm of wearable devices and human-machine interaction. However, challenges persist in the current status quo, including complicated fabrication processes, mutual constraints of sensitivity and detection range, and slow response times. In this study, we propose a low-cost and simple-to-manufacture flexible pressure sensor (BGSPS). 3D-printed composite origami structures are utilized as the dielectric layer, and the dielectric filler (barium titanate) and conductive filler (graphene) are doped into the dielectric layer to improve the capacitive response. Finite element simulations and practical experiments are utilized to systematically optimize the structural design parameters and investigate the content of the conductive and dielectric fillers. Due to the optimized origami-structured dielectric layer and the introduction of two materials, the BGSPS exhibits fast response/recovery times (25 ms/25 ms), high sensitivity (3.28 kPa^-1 in 0-10 kPa), a broad sensing range (0-437.5 kPa), and long-term stability (5000 cycles). Finally, BGSPS-based applications, including human motion monitoring, smart insole systems, and flexible sensing arrays, are demonstrated, proving the potential applications of the sensor in the domains of smart healthcare and human-computer interaction.