The latest aircraft created by an aerospace engineering team at the University of Florida can climb and bank - and can almost fit in the palm of your hand.
The successful testing of a 15cm latex and carbon fibre winged "micro air vehicle" is a step
forward for an ambitious initiative being pursued by the United States's Defense Advanced Research Projects Agency, which wants to develop tiny but affordable aeroplanes for use in battlefield surveillance.
In the United Kingdom, the Defence Evaluation Research Agency (Dera) is also interested in the technology.
Peter Ifju, assistant professor of aerospace engineering and a lead member of the Florida team, said that although other teams had made planes of this size before, the Florida design, inspired by the bat, stands out because of its use of cheap, off-the-shelf components. Each cost about Pounds 190.
"The military wants a plane the size of a small bird. We came up with design modifications that gave us control over our plane at very high angles of attack, which allowed us to shrink it to the target size without compromising manoeuvrability
or stability," Ifju said.
The US goal is for a plane that can fly quietly for at least 20 minutes, carrying a tiny video camera. This would allow troops to scout enemy positions without putting themselves at risk. The Florida engineers are now trying to devise an independent navigation system for the vehicle that does not require a remote-control operator.
Dera has been discussing such craft with British academics, including Cambridge University insect flight expert Charlie Ellington. A Dera spokeswoman said:
"News that a 15cm flying machine has been successfully developed is interesting, and we are undertaking a feasibility study into the role of unmanned air vehicles of all types as carrier platforms for sensor packages to detect chemical and biological agents."