Flexible microhyperboloids facets giant sensitive ultra-low pressure sensor

Abstract

We report a low-cost, flexible, and highly sensitive capacitive ultra-low pressure sensor using the micro-hyperboloid structure (mHBS). The flexible pressure sensor comprises of the PDMS (poly-dimethylsiloxane) elastomeric dielectric thin layer, and ITO (Indium Tin Oxide) coated PET (poly-ethylene tetra-fluoride) flexible conducting electrodes. The sensor with the hyperboloid structure shows the 0.1–96 % change in capacitance for 1 Pa to 100 kPa pressure range. With the capability of ultra-low pressure detection (1 Pa) and fast response speed (40 ms), this pressure sensor shows the sensitivity of 1.8 kPa−1 in the pressure range of 1 Pa–120 Pa. The sensitivity of the sensor was increased with the increase of its effective area, i.e., the sensor's sensitivity was 0.27 kPa-1, 0.99 kPa-1, and 1.8 kPa-1 for the effective area of 9 × 9 mm2, 12 × 12 mm2, and 15 × 15 mm2, respectively. Furthermore, the sensor shows excellent stability, responsitivity with low power consumption. These results indicate that the fabricated sensor based on the microhyperboloid structure surface of the elastomeric dielectric thin layer enhances the pressure sensor's performance and can be used as a wearable pressure sensor and is applicable for pressure sensing devices.