Hierarchically structured porous natural dielectric layer for sustainable pressure sensing, gesture monitoring, and detecting spatial pressure distribution

Flexible pressure sensors are essential in intelligent skins, healthcare monitoring systems, and soft robotics to bridge mechanical movements and electrical signals. Conventional pressure sensors, however, have a variety of challenges, including a complex fabrication method, increased cost, and biocompatibility issues. This work presents a novel bio-friendly, hierarchically structured porous natural dielectric material based capacitive pressure sensor featuring a maximum sensitivity of 0.0572 kPa⁻¹. The proposed pressure sensor uses a biofilm with a typically arranged honeycomb structure as a dielectric layer sandwiched between the Aluminum (Al) electrodes and incorporates polydimethylsiloxane (PDMS) encapsulation. With a 1.44 cm² sensing area, the device exhibits a response time (T_res) of 250 ms and a recovery time (T_rec) of 156 ms, functioning within a capacitive pressure sensing range of 0–110 kPa. This device monitors various human activities and stimuli and accurately detects pressure distribution and gesture recognition.