Ultrawide Sensing Range and Highly Sensitive Flexible Pressure Sensor Based on a Percolative Thin Film with a Knoll-like Microstructured Surface

Flexible pressure sensors have attracted considerable research interest and efforts owing to their broad application prospects in wearable devices, health monitoring, and human-machine interfacing. High-sensitivity, wide-workable-range, and low-cost pressure sensors are the primary requirement in practical application. In this work, flexible pressure sensors with high sensitivity in a wide pressure range are constructed by introducing a knoll-like microstructured surface into a percolative thermoplastic polyurethane/carbon black sensitive film, using a facile, efficient, and cost-effective screen-printing route. The prepared pressure sensors exhibit an ultrawide sensing pressure range of 0-1500 kPa, high sensitivity (5.205 kPa(-1) in the range of 0-100 kPa and 0.63 kPa(-1) over 1200 kPa), fast response, and excellent durability for more than 30 000 cycles. We demonstrated the applications of our pressure sensors in health monitoring, such as detection of wrist radial artery pulse waves, phonation, and vibrations. In addition, the proposed sensors showed the potential in object manipulation and human-machine interfacing, capable of detecting spatial pressure distribution, measuring grip forces, and monitoring gas pressures.