UAVs may have greener power source in solar cells

By integrating solar cells into the materials used to build unmanned aerial vehicles, the size and weight of the aircraft can be reduced and flight times increased.

The Air Force is studying ways to integrate solar technology into the materials used to build unmanned aerial vehicles, thus reducing the size and weight of the aircraft while lengthening flight time.

Funded by the Air Force Office of Scientific Research, researcher Max Shtein and his team at the University of Michigan are investigating several device applications, one being thin-film solar cells reshaped and coated onto long continuous filaments or fibers. Shtein is receiving $200,000 per year for five years to conduct the research.

The semiconductor-coated fibers can be woven into a fabric system used to form the structure of the UAV and generate the electricity to power it. Aircraft built with those materials would be light and compact, and the renewable energy source would power propulsion systems and on-board sensors and lengthen the aircraft's flight time.

To date, Shtein and his team have demonstrated the feasibility of the approach with small, stand-alone prototypes. However, using the idea on a large scale requires building more sophisticated fabrication equipment, so the researchers are developing a customized coating apparatus for making large quantities of fiber-based energy conversion devices.

Shtein also plans to develop models that combine optics, mechanics, electrical and energy transport, and energy storage mechanisms to reduce the bulk and weight associated with separate systems.