Nature Commun. 6, 8092 (2015)

To maximize the power output of flat solar cells, the panels can be tilted to track the position of the sun. But solar-tracking technologies are not widely used due to their high costs and often cumbersome structural components. This means that conventional tracking options are rarely even available for residential, pitched rooftop systems, which account for around 85% of installations. Inspired by the design principles of kirigami — the Japanese art of cutting paper — Aaron Lamoureux and colleagues have demonstrated a tracking system that is integral to the structure of the cell.

The team cut a relatively simple linear pattern into thin-film gallium arsenide solar cells. By pulling the cells along the direction perpendicular to the cuts, the structure buckled. This created arrays of tilted surface elements, whose angles were controllable to within one degree by simply changing the strain. The optical tracking efficiencies of such devices showed similar performance to conventional single-axis tracking systems. Requiring little more than a stretch, these designs could find their way into a range of optoelectronic devices.