SkinnyGuy writes with news of an invention out of Stanford that improves upon previous work: a transparent, stretchable, skin-like sensor that could have applications for prosthetic limbs and robotics. Quoting: "The sensor uses a transparent film of single-walled carbon nanotubes that act as tiny springs, enabling the sensor to accurately measure the force on it, whether it's being pulled like taffy or squeezed like a sponge. ... The sensors consist of two layers of the nanotube-coated silicone, oriented so that the coatings are face-to-face, with a layer of a more easily deformed type of silicone between them. The middle layer of silicone stores electrical charge, much like a battery. When pressure is exerted on the sensor, the middle layer of silicone compresses, which alters the amount of electrical charge it can store. That change is detected by the two films of carbon nanotubes, which act like the positive and negative terminals on a typical automobile or flashlight battery. The change sensed by the nanotube films is what enables the sensor to transmit what it is 'feeling.'"