Influence of the pore size on the sensitivity of flexible and wearable pressure sensors based on porous Ecoflex dielectric layers

The porous elastomer was used as the dielectric layer of flexible capacitive-type pressure sensors extensively to obtain high sensitivity, of which the pore size could play an important role in improving the sensitivity of sensors. Herein, the porous Ecoflex structures with various uniform pore sizes were fabricated to develop the flexible pressure sensors. The sensitivities of the as-prepared sensors depended on the interpore wall thickness of the porous Ecoflex in the low-pressure range (0–60 Pa). The sensor with the pore size about 150–200 μm exhibits a relatively high sensitivity (~1.096 kPa−1) in the low-pressure range. Meanwhile, the as-prepared sensors can be applied as wearable devices in detecting the pulses of the carotid artery, the heartbeats, and the hand movements.