Enhanced pressure sensors in supercapacitive–piezoelectric mixed mode with jelly-gel as dielectric layer

Degradable and bio-hydrogel have attracted increasing scientific interest due to their non-pollution properties, which are conducive to environmental protection and sustainable social development. In this study, a pressure sensor with jelly-gel as three-dimensional dielectric layer is fabricated based on biological carbon electrodes and peach juice electrolyte. The symmetrical biological carbon electrodes from flour are separated by jelly-gel with functional groups in 5 mm thickness, which not only has a supercapacity of 16.36 F g−1, but also shows a piezoelectric potential of 2 mV. Then, a supercapacitive–piezoelectric mixed working mode was developed that has a sensitivity of 1.24 kPa−1 which can be obtained in the range of 0–0.16 kPa, which is 6.89 times higher than the piezoelectric pressure sensor with the same thickness of the dielectric layer. Finally, based on its excellent performance, we have applied the supercapacitive–piezoelectric sensor to physiological signal monitoring and crop maturity monitoring experiments, which expands its application in intelligent biodegradable electronic devices and shows its wide application prospect.