Ultralow-Cost, High-Performance Paper-Based Flexible Pressure Sensor with High Sensitivity and Wide Working Range Inspired by Embossing Technique

Constructing rational three-dimensional (3D) microstructures in active layer is an extremely popular strategy to enhance the sensing performance of flexible pressure sensors. However, most of these technologies for constructing 3D microstructures require complex processes and high-cost, which hinder the commercialization of flexible electronics. Herein, inspired from the embossing concept in papermaking technology, we proposed a high-performance paper-based flexible pressure sensor with 3D embossed patterns. The multi-level microstructures of the paper were prepared by embossing, including fibrous network porous structure inside the paper and micro-bump pattern structure on the surface of paper. The density and geometry of embossed patterns strongly affects sensor performance. The as-fabricated flexible pressure sensor shows exceptional sensing performance, such as an ultrahigh sensitivity (74.092 kPa-1), a wide working range (0-200 kPa), a low detection limit (1.5 Pa), and a fast response time (80 ms), and an excellent durability (5000 cycles). Furthermore, the electromechanical mechanism was further revealed based on the equivalent circuit analyses and finite element analysis (FEA). Additionally, the omni-direction human motions, including physiological or somatic movements can be accurately detected by this flexible pressure sensor. This facile, low-cost, scalable, and sustainable design strategy provides a new direction for the commercialization of flexible electronics.