The sense of touch can help robots recognize objects, perform delicate tasks and avoid collisions. However, while much effort is being put into developing the robots' vision and hearing skills, Herish noted that their sensitivity to touch has so far remained very basic.
Benny Ran and Avi Blizovsky
Robots will soon wear touch-sensitive electronic skin, which Japanese scientists are developing. "Touch recognition is of great importance in the next generation of robots," says Takao Sumiya from the University of Tokyo, who developed the skin. The sense of touch can help robots recognize objects, perform delicate tasks and avoid collisions. However, while much effort is being put into developing the robots' vision and hearing skills, Herish noted that their sensitivity to touch has so far remained very basic.
The human skin contains a battery of touch receptors, which transmit signals to the brain through the nerves as soon as they are pressed. To sense a gentle touch, the main sensors are equipped with tiny bubbles made of a layer of tissue called Meissner cells. The scientists created plastic replicas of the human receptors, which in response to pressing create an electric field - similar to the touch-sensitive panels known, among other things, from computer input devices and elevator buttons.
However, it is not enough for the electronic skin to be able to sense pressure - it must identify precisely where the pressure was applied. Therefore, the skin must be covered with a surface of individual sensors, each of which sends a signal when pressed. Soumya and his colleagues wired a skin consisting of a sheet of polymeric rubber, covered with flakes of electrically conductive graphite. The electrical resistance of the sheet changes with pressure, and the change is detected by an array of transistors installed under the rubber.
The main challenge is to make the system as flexible as real skin, so that it can be wrapped around the robot's limbs. Conventional transistors and microprocessors, which are made of silicon, are hard and fragile - therefore Soumya and his colleagues produced them from a flexible organic material. The result is a skin that can be bent sharply without damaging the transistors, and it continues to function normally even when wrapped around a rod only 2 mm thick.
The Japanese team hopes to add additional features of the human skin to the system in the future, such as temperature and humidity detection. The team also hopes that in the future it will also be possible to stretch the electronic skin - which today, like a sheet of paper, can be folded but not stretched.
