June 20, 2012 – HIGH TECH – The kinds of drones making the headlines daily are the heavily armed CIA and U.S. Army vehicles which routinely strike targets in Pakistan – killing terrorists and innocents alike.
But the real high-tech story of surveillance drones is going on at a much smaller level, as tiny remote controlled vehicles based on insects are already likely being deployed.
Over recent years a range of miniature drones, or micro air vehicles (MAVs), based on the same physics used by flying insects, have been presented to the public. The fear kicked off in 2007 when reports of bizarre flying objects hovering above anti-war protests sparked accusations that the U.S. government was accused of secretly developing robotic insect spies.
Official denials and suggestions from entomologists that they were actually dragonflies failed to quell speculation, and Tom Ehrhard, a retired Air Force colonel and expert on unmanned aerial craft, told the Daily Telegraph at the time that ‘America can be pretty sneaky.’
The following year, the U.S. Air Force unveiled insect-sized spies ‘as tiny as bumblebees’ that could not be detected and would be able to fly into buildings to ‘photograph, record, and even attack insurgents and terrorists.’
Around the same time the Air Force also unveiled what it called ‘lethal mini-drones’ based on Leonardo da Vinci’s blueprints for his Ornithopter flying machine, and claimed they would be ready for roll out by 2015.
The SWARMS goal is to combine swarm technology with bio-inspired drones to operate ‘with little or no direct human supervision’ in ‘dynamic, resource-constrained, adversarial environments.’ Nano-biomimicry MAV design has long been studied by DARPA, and in 2008 the U.S. government’s military research agency conducted a symposium discussing ‘bugs, bots, borgs and bio-weapons.’ Researchers have now developed bio-inspired drones with bug eyes, bat ears, bird wings, and even honeybee-like hairs to sense biological, chemical and nuclear weapons.
Flapping-wing robotic insects are small, highly maneuverable flying robots inspired by biological insects and useful for a wide range of tasks, including exploration, environmental monitoring, search and rescue, and surveillance. Recently, robotic insects driven by piezoelectric actuators have achieved the important goal of taking off with external power; however, fully autonomous operation requires an ultralight power supply capable of generating high-voltage drive signals from low-voltage energy sources. This paper describes high-voltage switching circuit topologies and control methods suitable for driving piezoelectric actuators in flapping-wing robotic insects and discusses the physical implementation of these topologies, including the fabrication of custom magnetic components by laser micromachining and other weight minimization techniques. The performance of laser micromachined magnetics and custom-wound commercial magnetics is compared through the experimental realization of a tapped inductor boost converter capable of stepping up a 3.7V Li-poly cell input to 200V. The potential of laser micromachined magnetics is further shown by implementing a similar converter weighing 20mg (not including control functionality) and capable of up to 70mW output at 200V and up to 100mW at 100V.