Researchers at the University of Pennsylvania unveiled the world’s first solar-powered circuit in a January edition of ACS Nano. The technology shows particular promise for touchscreen devices, which could use the circuits as a direct source for sun-power. Not to be confused with solar cells, which convert sunlight energy to electricity and store it for later, this breakthrough involves circuits—electrical devices that provide paths for electricity to flow. This means that sunlight absorbed by the device can immediately use the energy to power the device.

Here’s how the circuit works: Electrons, here known as surface plasmons, oscillate on tiny molecules called nanoparticles. These plasmons act as a ’super lenses,’ which gather all solar light hitting the circuit. Once the light’s collected, the particles pose as electrodes to ferry away the electricity for a device to use.

Currently, though, researchers can only produce and harness small amounts of energy from the photovoltaic circuits, nowhere near enough to power consumer electronics. But scientists are sure power production will only increase in the future with creative methods like stacking circuits to absorb and focus more light energy.

Self-charging photovoltaic circuitry might be used in display screen pixels or painted on the outside of iPads and smartphones to scavenge sunlight and charge the devices, according to Dawn Bonnell, a researcher on the project. It also could potentially offer just the right power solution for small robotic devices or help computers operate on light alone.

For now, the circuits still represent a fairly major scientific breakthrough to the researchers, one science has grappled with for some time. When working with microscopic parts, invisible to the eye, it’s hard for scientists to ensure each component is the right distance away from the others to form a proper circuit. Molecules must be connected to particles, and particles must be separated from one another by a molecule-long space.

Silicon circuits aren’t likely to be replaced in the near future, Bonnell says, but this breakthrough could one day make phone chargers much less necessary—at least on sunny days.

Courtesy of Cassie Rodenberg, Popular Mechanics