Multilayer Flexible Pressure Sensor With High Sensitivity Over Wide Linearity Detection Range (August 2021)

Flexible pressure sensors have attracted significant attention in both academic and industrial fields. However, how to design and fabricate a flexible pressure sensor having high sensitivity and good linearity in a wide detection range is still a challenge. To address this challenge, this article proposes a flexible piezoresistive pressure sensor with a multilayer structure consisting of microstructured composite layers (MCLs), which are sandwiched by indium tin oxide-polyethylene terephthalate electrodes and encapsulated by an ultrasoft elastomer frame. The preparation of the conductive composite and the fabrication procedure of the pressure sensor are presented. Due to the point-to-point hemisphere microstructures of the multilayer composite layers, the pressure sensor can perceive pressure with a sensitivity of 7.66 kPa ⁻¹ in a range of 0–583 kPa. Besides, the proposed sensor features good linearity of 5.86% and an $R^{2}$ of 0.99. The developed pressure sensor has excellent repeatability of 500 cycles and a fast response time of 80 ms. The proposed sensor is verified by the experiments with primary applications, and the obtained results indicate it could be potentially utilized as wearable detectors.