The touch device has been created by researchers in America who used nanoparticles to sense the contours of a coin. It is accurate enough to detect the outline of Abraham Lincoln's face on a 1c coin and the letters TY in the word Liberty. To make the sensor, the researchers built up a film consisting of alternate layers of gold and cadmium sulfide nanoparticles with a thin plastic sheet on top and glass below. An object is placed on the plastic and an image sensor beneath the glass reads the changes in electrical current and electroluminescence caused within the nanoparticle...