Flexible capacitive pressure sensors with porous double microstructured layers

Abstract

In this study, a flexible capacitive pressure sensor was developed, featuring a dielectric layer composed of a polydimethylsilane (PDMS)/BaTiO3/SrTiO3 composite material. The electrode and dielectric layers were structured with a dual microstructure, combining diagonal and sandpaper-porous elements. Additionally, nano-barium titanate (BT) powder, known for its relatively high dielectric constant, was incorporated into PDMS, along with an appropriate amount of strontium titanate (STO), to enhance the sensor's sensitivity. The developed sensor exhibited a remarkable sensitivity of 2.681 kPa–1, with response and release times of approximately 39 ms and 61 ms, respectively. It demonstrated a low detection threshold and withstood over 5000 compression cycles, showcasing excellent repeatability. The results underscored the sensor's robust pressure-sensing performance, making it suitable for diverse applications, including human pulse monitoring, heartbeat tracking, robot arm sensing, object weight detection, and real-time healthcare monitoring.