Flexible Sensors Make Robot Skin From: Technology Research News - 09/29/2004 By: Eric Smalley Recreating the pressure sensitivity of skin for robots and other objects is the goal of a University of Tokyo research project using pressure sensor arrays that can be widely distributed due to their fabrication from cheap organic or polymer transistors on a flexible material. Potential applications of the technology suggested by University of Tokyo electrical engineering professor Takao Someya include pressure carpets that can identify people, in-vehicle systems for monitoring motorists' mental and physical health, and an artificial epidermis to facilitate more sensitive interaction between robots and their environments. The researchers have developed a prototype eight-centimeter-square sheet comprised of a 32 by 32 array of organic pressure sensors supporting a density of 16 sensors for every square centimeter. Conductive graphite particles in the prototype's pressure-sensitive rubber layer cause its electrical resistance to shift in response to pressure, while the layer and a copper electrode are enameled to an array of organic transistors. Only one transistor operates for each activated sensor thanks to an active matrix design, making the array less power-consumptive than a simpler array in which sensors are wired into a grid. The active-matrix control scheme makes the arrays intelligent enough to permit individual sensors at specific feedback points to check the heartbeat and respiration rate of collapsed hospital patients, for example, enabling the skin to determine whether the patient is simply resting or is in trouble, according to Someya. Organic transistors' inexpensiveness can offset their increased size and slower performance compared to silicon transistors. Someya expects electronic skin to be ready for practical applications in about half a decade. http://www.trnmag.com/Stories/2004/092204/Flexible_sensors_make_robot_skin%20_092204.html