High-Sensitivity and Broad Linearity Range Pressure Sensor Based on Printed Microgrids Structure

Flexible pressure sensors with high sensitivity across a wide linear range and a large array are in high demand for applications in electronic skin, physiological monitoring, and human-machine interfaces. Inspired by the ink drawing phenomenon, a one-step screen-printing method for preparing controllable microgrid structures is applied to the production of pressure-sensitive films. This study reports the preparation of a flexible piezoresistive pressure sensor using printed microgrid arrays created by screen printing a polyvinyl chloride/carbon black paste. Reducing the area ratio of the microstructure to polyvinyl chloride/carbon films significantly reduces the compressive ability of the microstructure. Consequently, the contact area with the electrode increased, thereby leading to high sensitivity and a broad sensing range. The findings of this study suggest that the printed pressure sensor with microgrids demonstrated excellent sensitivity (8.46 kPa<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula>) and linearity (coefficient of determination, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R} ^{{2}} =0.999$ </tex-math></inline-formula>) in the range of 0–110 kPa. It also exhibited a fast response time of 42 ms, high stability, excellent durability over 1000 cycles, and low hysteresis. In addition, the printed sensor was found to accurately detect the human wrist pulse, and the printed array pressure sensors detected the complex pressure distribution states.