Flexible Pressure Sensor With High Sensitivity and Fast Response Based on Bionic Honeycomb-Structured Polydimethylsiloxane/Aluminum Oxide Composites Dielectric via 3-D Printing

Although capacitive pressure sensors have been widely used in tactile sensing, human-computer interface, and medical applications, the viscoelastic and incompressible characteristics of the dielectric layer continue to be the primary limiting factors for achieving high sensitivity and fast response times. In this study, we propose a new flexible capacitive pressure sensor (FCPS), with a bionic honeycomb structure as a dielectric layer structure via 3-D printing and optimize its architecture through finite element simulation. Aluminum oxide (Al $_{\text{2}}$ O $_{\text{3}}$ ) nanoparticles with a high dielectric constant were chosen to be doped into the PDMS to form the dielectric layer. Owing to the optimized bionic honeycomb structure and the incorporation of high-dielectric material, the PDMS/Al $_{\text{2}}$ O $_{\text{3}}$ -based flexible capacitive pressure sensor (PAFPS) exhibits high sensitivity ( $\sim$ 1.75 kPa $^{-\text{1}}$ in the range of 0–1 kPa and 0.045 kPa $^{-\text{1}}$ in the range of 1–200 kPa) and rapid response time ( $\sim$ 37.5 ms), which represents a significant improvement compared to previous reports. Furthermore, the successful application of PAFPS in various scenarios has provided valuable insights for the advancement of next-generation wearable electronic devices.