Single-atom-thick materials are exciting, because they open up new possibilities for materials science, like making tiny transistors. Molybdenum disulfide is particularly interesting because of its potential as a thin transistor incorporated into other materials. Now that scientists have shown atom-thin layers of it can generate electricity, future designers and engineers might incorporate it into very small and self-powering machines. Because it needs to stretch to generate power, it might not work well on a tablet-like device, but imagine it built into a shoe with a display that can tell how many steps you've made that day.