We’ve seen the development of a number of technologies that could be used to provide robots with a sense of touch, such as proximity and temperature sensing hexagonal plates and artificial skin constructed from semiconductor nanowires. However, perhaps none are as impressive as a tactile sensor developed by researchers at the University of California’s Viterbi School of Engineering. The group’s BioTac sensor was built to mimic a human fingertip and can outperform humans in identifying a wide range of materials, offering potential use for the technology in robotics and prostheses.
The finger-sized BioTac sensor consists of a soft, flexible skin covering a liquid filling. The skin even has fingerprints that enhance the sensor’s sensitivity to vibration, so that as the sensor slides over a textured surface, it vibrates in characteristic ways. A microphone designed to be used underwater – known as a hydrophone – located within the sensor’s bone-like core detects these vibrations, similar to the way in which a human finger uses similar vibrations to recognize textures. However, the robot finger is even more sensitive and also has the capability to identify in which direction forces are being applied and the temperature of the object being touched.