Effect of Surface Temperature on Finger Friction and Perception in Electroadhesion

Electroadhesion, which modulates finger friction force through electrostatic force, is a widely used surface haptic approach for touch-based applications due to an absence of moving parts and wide bandwidth. Although there have been many studies on the electronics and mechanics of electroadhesion, little is known about how surface temperature variation or purposeful temperature modulation influences electroadhesion. Here we study the effect of surface temperature on electroadhesion, especially absolute threshold voltage to perceive the electroadhesion through psychophysical experiments followed by friction measurements to understand the physics behind the results. We found that the threshold voltage is lower at a higher temperature due to different frictional behaviors of the fingerpad at different temperatures.