Enlarge Image Energized. Spiking a conventional thermoelectric material with sodium and selenium creates regions in the crystal that conduct electricity more readily (blue and gold), boosting the material's performance. Credit: Adapted from Y. Pei et al., Nature, 473 (5 May, 2011) Engineers have come up with a handful of uses for computer chip-like devices that chill objects when plugged in or convert waste heat into electrical power—stuff like car seats that cool drivers on hot days and coolers that chill drinks when plugged in. But by-and-large, these devices, known as thermoelectrics, have remained too inefficient to make much of...