Reading Researchers have developed a sensitive layer material that is so sensitive that it can even detect the steps of a ladybird. Beetles also provided the model for the structure of the sensor: Like the wings of insects, the artificial material is made up of layers of tiny hair structures that interlock. In beetles, this ensures the flexible stability of the wings, in the case of the sensor the hairs release pulses when pressed. The sensitive material is ideal for fine-touch robotics and prosthetic techniques, say Kahp-Yang Suh of Seoul National University and colleagues. The "hairs"? of the sensor material are only about 100 nanometers thick. By comparison, a human hair has a diameter of approximately 80, 000 nanometers. The tiny bristles made of polymer fibers are coated with a touch of metal to make them electrically conductive. They sit on a polymer layer so that the material can be placed in a kind of sandwich structure in which the hairy sides mesh. Now when the material is squeezed, the hair structures bend slightly, thereby changing their electrical resistance, as indicated by attached meters.
Even the direction of pressure is detected
According to the researchers, the system not only surpasses the sensitivity of human skin, it also performs another key function of its natural role model: the differential perception of pressure, shear and torsion forces. "Human skin can distinguish different stress directions, but most artificial sensors can not do that yet, " says Suh. For the subtlety of a technical sense of touch, however, this spatial perception ability is decisive.
The new material could thus be used to equip prostheses or grippers of robots with even more tact, the developers say. But other applications could obviously benefit from the technology: the research group is said to be talking to a healthcare company that wants to develop devices for monitoring the heartbeat with the new material. display