The US Air Force Office of Scientific Research is funding a project to incorporate solar power into unmanned aerial vehicles (UAVs) to make them more energy efficient.

Through the research, the air force plans to develop materials for building UAVs that power their propulsion systems and on-board sensors from solar energy.

The University of Michigan is trying to develop solar-cell-coated fibres that can be used to form the body of the UAV and generate electricity at the same time, enabling the craft to have a longer flying time.

Although it is possible to create such coated fibres, more sophisticated fabrication equipment is needed to integrate solar cells in the desired configuration.

The university team is attempting to make a customised coating apparatus for producing large quantities of fibre-based energy conversion devices.

Once such an apparatus is created, new models will be designed integrating optics, mechanics, electrical and energy transport, and energy storage mechanisms.

Combining these functions will also make the UAVs lighter and more compact.

A $200,000-a-year grant has been awarded for this five-year project.