Solar Cells Increase UAV Stamina, Flight Time

  • Published
  • By Dr. Michael Durstock
  • Materials and Manufacturing
WRIGHT-PATTERSON AIR FORCE BASE, Ohio --  Unmanned air vehicles (UAVs) are getting a power boost thanks to a partnership between the Air Force Research Laboratory and Microlink Devices Inc., which has developed technology to integrate lightweight, flexible, high-efficiency solar cells onto a UAV platform. The additional power provided by solar cells to UAVs with electrically powered propulsion systems will increase their endurance and flight time; in addition, special operations personnel will benefit by added field surveillance capabilities.

Advanced solar cell technology is expected to extend the potential daytime flight capability of a variety of small, hand-launched UAVs used by special forces for situational awareness in combat areas. Currently, AFRL is working with Microlink Devices Inc., a solar cell manufacturer, to demonstrate this capability on the Raven platform, made by Aerovironment. AFRL engineers are developing three identical prototype Solar Raven UAVs, which they expect will operate up to 300 percent longer than those now in use.

The Raven is a small, hand-launched, remote-controlled aerial vehicle powered by an electric motor. It can fly up to 6.2 miles at altitudes of 10,000 to 15,000 feet, and obtain speeds of 28 to 60 miles per hour. Currently, the Raven is powered by a lithium ion battery and has a flight time of approximately one hour.

The solar-powered Raven program, initiated by AFRL's Nanostructured and Biological Materials Branch, was designed to integrate lightweight, flexible, high-efficiency solar cells onto the wings of the UAV to harvest solar energy and extend vehicle flight times. The 20-square-centimeter solar cells adhere to the wings of the vehicle with a thin plastic film and adhesive. The wing of a solar-power-enabled vehicle is expected to carry anywhere from 80 to 100 cells.

AFRL researchers recently briefed the solar-powered Raven's progress to the United States Special Operations Command (USSOCOM), Special Operations Research, Development and Acquisition Command Science and Technology Office, fixed and rotary wing representatives, and Air Force Special Operations Command (AFSOC). Special Forces are a significant user and supporter of both solar- and battery-powered technologies, and USSOCOM proposed a program for AFRL to establish an industrial base for both solar cells and conformal batteries, which would be incorporated into the Raven. Flight demonstrations will be conducted by both AFSOC and USSOCOM through their Technical Network Topology venue where Special Operations Forces demonstrate and test promising new technologies.