Robot 'finger' more sensitive than human's

Researchers in California say a robot equipped with a sensor to mimic the human fingertip has a touch more sensitive than a human's. The specially designed robot can outperform humans in identifying a wide range of natural materials according to their textures, creating the possibility of advancements in prostheses, personal assistive robots and consumer product testing, the University of Southern California reported Tuesday. The robot's sensor can also tell where and in which direction forces are applied to the "fingertip" and even the thermal properties of an object being touched, researchers said. USC's BioTac sensor has a soft, flexible skin over a liquid filling. As the finger slides over a textured surface, the skin vibrates in characteristic ways and a hydrophone inside the bone-like core of the finger detects those vibrations. The human finger uses similar vibrations to identify textures, the researchers said, but the robot finger proved even more sensitive. When presented with common materials gathered from fabric, stationery and hardware stores, the robot could correctly identify the material 95 percent of the time, they said.