To improve the sensitivity of piezocapacitive pressure sensors, the thickness of the dielectric layer must vary with exposure to a weak force, and the mechanical modulus must be low. We propose a simple method for trapping air bubbles in an elastomer to reduce the modulus of the elastomer. The sensitivity of the pressure sensors fabricated from the air bubble-trapped elastomer is approximately 10 times better than that of a pressure sensor without air bubbles. The pressure sensor with air bubbles has a very high linear response to external pressure changes. We also demonstrate that the pressure sensor fabricated from the air bubble-trapped elastomer can detect the dynamic loading and unloading pressure of a small Lego toy and a small M6 bolt. These results show that our pressure sensor based on the air bubble-trapped elastomer can be used to detect applied pressures or contact forces of electronic skin (e-skin).

• Received 10 September 2018
• Revised 30 November 2018

DOI:https://doi.org/10.1103/PhysRevApplied.11.014037