Ambient light may be all you need to charge your phone. Small, thin and flexible panels created with an inkjet printer can harvest energy from artificial light and sunlight.
Conventional solar panels typically use silicon to capture the sun’s energy. But Sadok Ben Dkhil from Dracula Technologies and his team have developed a conductive plastic that can capture a wider range of wavelengths. “Our material can capture energy from indoor light, which isn’t possible with silicon,” says Ben Dkhil. The device is lightweight, non-toxic and can even be folded, which is not the case for silicon solar cells.
The panels are made up of five layers printed on top of each other. A photoactive layer is sandwiched between two semiconductor sheets that help a conductive ink in the outer layer to extract the charge. A square module, 5 centimetres across can be printed in about an hour. The largest panels they plan to create are 30-centimetre squares.
Using inkjet printing allows light-capturing panels to be produced at low cost. “It’s the cheapest fabrication technique,” says Alexander Colsmann from Karlsruhe Institute of Technology in Germany who is developing similar systems.