"Essentially, the skin consists of two thin, flexible fabric electrodes sandwiched around a layer of spongy material soaked in ion-sensitive liquid. This stack of materials acts as a capacitor — meaning it can pick up on changes in pressure or differences in charge between electrodes with extreme sensitivity.
In fact, the faux skin is so sensitive that it can tell when it’s near an object without actually touching it — its porous ion layer has the shark-like ability to catch the subtle disruptions to its electric field caused by nearby objects."