High‐Performance Pressure Sensor Based on Flexible Paper with Composite Carbon Ink/Carbon Nanotubes

Abstract

Flexible wearable sensors have increasingly contributed to human health detection and physiological signal acquisition in recent years. Nevertheless, developing high‐performance sensors that can achieve high sensitivity and wide detection range and align with environmentally friendly principles remains a significant challenge. Herein, a novel flexible paper‐based pressure sensing platform, in which the conductive layer is made of paper with a dome structure on top, is demonstrated. The dome structure functions similarly to microstructures created via complex processes, both enhancing sensor sensitivity. The conductive material selected is carbon ink and carbon nanotubes, offering the benefits of cost‐effectiveness and high conductivity. In the results, it is shown that the sensor has high sensitivity (6.78 kPa −1 , <10 kPa), a linearity of 0.99 under 10 kPa, low lower limit of detection, and a dynamic response (157 ms) and demonstrates good repeatability over 1000 cycles. Due to its high sensing performance, the sensor effectively detects both subtle and large human motions. This exceptional performance is attributed to the rough fibers on the paper's surface and the protruding dome structure, both of which enhance the sensor's ability to sense pressure signals. The paper‐based sensors proposed in this study offer an economical and environmentally friendly solution with significant potential in human detection.