Two scientists at Spain's Polytechnic University of Cartagena have created a robotic finger with a sense of touch, using electrosensitive "smart materials" .
It is made of a polymer that can feel the weight of what it's pushing and adjust the energy it uses accordingly. This is similar to the way we use our sense of touch. If we pick up a delicate object such as a flower, our fingertips sense its fragility and so grasp it lightly. We instinctively exert more force when holding or moving a heavier, more robust item because there is feedback between our sensations and muscles.
One way to make an artificial touch-sensitive limb, therefore, would be to equip it with delicate pressure sensors to provide this sort of feedback.
