Tiny silicon wings could power future micro-drones
- By Henry Kenyon
- Jun 22, 2011
Tiny silicon dragonflies could one day be winging through disaster sites to detect radiation or chemicals, thanks to the nearly microscopic dragonfly that was one of the winners of a student design contest sponsored by Sandia National Laboratories.
Students from Texas Tech University used microelectromechanical systems (MEMS) technology to design the device, which can be manufactured out of polysilicon. Current micro-airbots range from about 1 centimeter to 15 centimeters — or 10 millimeters to 150 millimeters. By contrast, the silicon dragonfly’s wings would be about 0.5 millimeters long (about the width of five human hairs) and 0.1 millimeter wide.
The students used biology for inspiration. A small electric current would cause the dragonfly wings to thermally expand and contract, which would make them flap and thereby generate thrust.
Sandia officials said the students’ approach opens up new ways of designing flying robots that could be used in a variety of scientific and military applications, such as mapping radiation leaking from damaged nuclear reactors or spotting enemy positions.
Another contest winner was a highly efficient microvalve designed by students from Carnegie Mellon University. Valves typically have a screw-based motion, such as those in a shower or kitchen sink, or they are switch-based, such as the ball and flapper valves used in toilets and artificial heart valves.
The students’ microswitch-based valve is highly sensitive and would allow scientists to control very small amounts of liquid flow. The MEMS-based system would need only picojoules of energy to switch its state. (A picojoule is 1 million millionth of a joule; a joule is equal to the work required to produce 1 watt of power for one second.) The valve's design could lead to the creation of flow-through microvalves for use at biological research facilities and medical centers to quickly analyze a patient’s health from very small fluid samples.
Sandia will fabricate the dragonfly, microvalve and other student-submitted designs at the laboratory’s Microsystems Engineering Sciences and Applications silicon fabrication facility. The parts will then be returned to the students for testing to determine if the final products match their original design specifications.