Insect-sized drones would find many uses in completing time-consuming tasks—if only they could slip off their leashes. The electronics needed to power and control these miniature robots are too heavy for the devices to lift without the use of a tether, which limits the robot’s range and functionality.
A team of engineers at the University of Washington may have come up with a solution: RoboFly, a bug-sized machine, weighing only slightly more than a toothpick that can fly without a tether.
The main engineering challenge for a robot like this was the flapping wings. The propellers used by larger drones become ineffective when miniaturized. The best option for an insect-sized robot would be to fly like an insect—with flapping wings. But flapping a wing requires a lot of power, and the machinery needed is too big and bulky for the tiny robot to lift.
The engineers may have solved that problem by changing the way the drone is powered: charging the machine’s photovoltaic cell with a laser beam. The laser alone doesn’t provide enough voltage to make the drone work, so the team designed a circuit that boosts the seven volts generated by the cell up to the 240 volts needed for flight.
“It was the most efficient way to quickly transmit a lot of power to RoboFly without adding much weight,” said Shyam Gollakota, associate professor in the university’s Paul G. Allen School of Computer Science & Engineering.
To allow RoboFly to control its own wings, the engineers added a microcontroller to the circuit.
“The microcontroller acts like a real fly’s brain telling wing muscles when to fire,” said co-author Vikram Iyer, a doctoral student in the university’s Department of Electrical Engineering.
RoboFly can only take off and land, and it runs out of power quickly when the laser is turned away. The robot’s creators are working on ways to steer the laser so the drone can hover and fly.
Future versions could use tiny batteries or derive energy from radio frequency signals. In addition, the team anticipates that more advanced brains and sensor systems would help the robots better navigate and take on more complex tasks.
A swarm of these tiny drones could do the work that larger drones would be unable to, such as finding leaks in methane pipes, surveying crop growth up close and searching collapsed buildings to assist with rescue efforts.
“Before now, the concept of wireless insect-sized flying robots was science fiction,” said co-author Sawyer Fuller, assistant professor in the Department of Mechanical Engineering. “Our new wireless RoboFly shows they’re much closer to real life.”
Read more about robots inspired by insects at How Insect Wings Could Lead to Better Machines.