Transparent, power-producing crystals could lead to invisible robots, self-powered touch screens

Robert Service in Science:

Hit certain crystalline materials with a jolt of electricity and they will change shape. Squeeze them and they will jolt you right back. Scientists have used these so-called piezoelectrics for decades in ultrasound medical imaging; the materials are so sensitive that they can pick up the motion of sound waves moving through tissue. Now, researchers have come up with a simple new way to make potent transparent piezoelectrics, which could lead to improved medical imagers, invisible robots, and touch screens that power themselves.

Piezoelectrics are made up of either myriad tiny crystallites or single crystals of a variety of materials including ceramics and polymers. In both cases, a mix of atoms arrange themselves into a simple crystalline unit—typically the size of a handful of atoms—that’s repeated over and over. Inside each of these building blocks, the atoms are arranged in a so-called electric dipole, with more positive charges on one side and more negative charges on the other.

…That improved performance could lead to more sensitive photoacoustic imaging devices, which could aid doctors in everything from breast cancer and melanoma detection to the tracking of blood flow for the treatment of vascular diseases, Kothapalli says. Chen and his colleagues report that the advance could also inspire transparent actuators for invisible robotics and screens that power themselves when touched.

More here.