An aerial robot weighing 4 grams is powered by tiny solar panels that produce extremely high voltages – an approach that could enable drones to fly indefinitely
A drone weighing just 4 grams is the smallest solar-powered aerial vehicle to fly yet, thanks to its unusual electrostatic motor and tiny solar panels that produce extremely high voltages. Although the hummingbird-sized prototype only operated for an hour, its makers say their approach could result in insect-sized drones that can stay in the air indefinitely.
Tiny drones are an attractive solution to a range of communications, spying and search-and-rescue problems, but they are hampered by poor battery life, while solar-powered versions struggle to generate enough power to sustain themselves.
As you miniaturise solar-powered drones, their solar panels shrink, reducing the amount of energy available, says Mingjing Qi at Beihang University in China. The efficiency of electric motors also declines as more energy is lost to heat, he says.
To avoid this diminishing cycle, Qi and his colleagues developed a simple circuit that scales up the voltage produced by solar panels to between 6000 and 9000 volts. Rather than using an electromagnetic motor like those in electric cars, quadcopters and various robots, they used an electrostatic propulsion system to power a 10-centimetre rotor.
Source: NewScientist