Influence of cross-sectional geometry on the sensitivity and hysteresis of liquid-phase electronic pressure sensors

Cross-sectional geometry influences the pressure-controlled conductivity of liquid-phase metalchannels embedded in an elastomer film. These soft microfluidic films may function as hyperelastic electric wiring or sensors that register the intensity of surface pressure. As pressureis applied to the elastomer, the cross-section of the embedded channel deforms, and theelectrical resistance of the channel increases. In an effort to improve sensitivity and reducesensor nonlinearity and hysteresis, we compare the electrical response of 0.25 mm² channels with different cross-sectional geometries. We demonstrate that channels with a triangular or concave cross-section exhibit the least nonlinearity and hysteresis over pressures ranging from 0 to 70 kPa. These experimental results are in reasonable agreement with predictions made by theoretical calculations that we derive from elasticity and Ohm's Law.