Insect-size, camera-bearing unmanned aerial vehicles (UAVs) are being developed that could help in emergency situations considered too dangerous for people or in covert military surveillance missions.

Richard Bomphrey, from the University of Oxford’s zoology department, is leading this research, which is generating new insight into how insect wings have evolved over the past 350 million years. The work is supported by the Engineering and Physical Sciences Research Council, the main UK government agency for funding research and training in engineering and the physical sciences.

“Nature has solved the problem of how to design miniature flying machines,” Bomphrey said. “By learning those lessons, our findings will make it possible to aerodynamically engineer a new breed of surveillance vehicles that, because they’re as small as insects and also fly like them, completely blend into their surroundings.”

Currently, the smallest of state-of-theart fixed-wing unma n n e d surveillance vehicles are around a foot wide. The incorporation of flapping wings is the secret to making the new designs so small. To achieve flight, any object requires a combination of thrust and lift. In man-made aircraft, two separate devices (engines and either fixed or rotating wings) are needed to generate these — this limits the scope for miniaturising flying machines.

But an insect’s flapping wings combine both thrust and lift. If man-made vehicles could emulate this more efficient approach, it would be possible to scale down flying machines to much smaller dimensions than is currently possible.

The team’s groundbreaking work has attracted the attention of NATO, the US Air Force and the European Office of Aerospace Research and Development. The research is expected to produce findings that can be used by the defence industry within three to five years, leading to the development and widespread deployment of insect-size flying machines within 20 years.