A new technology allows heat to be transferred into energy - by first turning it into sound. With current technology, heat uses convection currents to turn a turbine (like steam passing through a turbine). This heat must be fairly hot however.
With the new technology, ambient heat is captured in high-surface area objects, like glass wool. This resonates - like blowing over a bottle, or into a woodwind instrument - and this resonance forms a single sound wave and that in turn generates voltage.
Heat engines have been around for decades, but they have always been large and impractical. With new advancements, they are now only milimetres in size - and as energy efficient as diesel engines. They can be used in conventional engines and machinery to recapture waste heat, but more enticingly, they could be used to create a new generation of solar power. Current solar panels take a very long time to pay off the energy costs of their own creation. Improved, efficient solar panels could open up massive new sources of energy - and the technology is bound to only improve.
Article in Science Daily.
Article in New Scientist.