(Credit: Kevin Ma/Pakpong Chirarattananon)
A tiny flying robot the size of a house fly is helping scientists study the dynamics of insect flight.
So far this year, we've seen an Harvard Microbiotics Laboratory, in a team led by graduate students Kevin Ma and Pakpong Chirarattananon, has created tiny, housefly-sized robots for the purpose of studying insect flight.that can mimic the complex flight patterns of its real-life counterpart from German robotics company Festo, and
Small flying insects like flies are capable of extremely agile manoeuvres, such as dodging out of the way of an incoming fly swatter, or landing on flowers and grass that are moving in the wind — making their flight difficult to replicate in a laboratory condition. But by using some unconventional approaches to propulsion, manufacturing and actuation, the Harvard Microbiotics team — after a decade's work — has been able to create a robot that can hover on the spot, take off vertically and steer. They're called RoboBees.
When the RoboBee took flight at 3am one morning mid-last year, it was a massive breakthrough. "I was so excited, I couldn't sleep," said Chirarattananon. Since then, the team has been aggressively testing the RoboBees, getting them to perform their aerial dances. They have gone through 20 of the robots in the last six months alone — but by now, the manufacturing process has been refined. Using a technique they call pop-up manufacturing, the team layers sheets of laser-cut material into a thin plate that folds up to form the complete structure of the robot.
Using piezoelectric actuators — strips of ceramic that expand and contract under an electrical current — the RoboBee is able to flap its two wafer-thin wings at a rate of 120 beats per second. Plastic hinges embedded in carbon fibre serve as joints, while a control system commands the rotational flapping motion of the wings, each wing controlled independently in real time. The robots are powered by a small, off-board power source that gauged the insect uses around 19 milliwatts of electricity during flight — consistent with the energy a real insect would use to fly.
The RoboBees have to remain tethered to the power source, since no battery solutions are commercially available that are small enough to allow the robots independent movement (not yet, anyway). Control is also wired in from a separate computer.
By studying a robot of this size and capability, the team can gather data to feed into future studies of flight and miniaturised power. Potential applications for the RoboBee itself could include environmental monitoring, search-and-rescue and crop pollination. Harvard, along with the Wyss Institute, Harvard's division, is already looking at ways to commercialise the technologies involved.
"Harnessing biology to solve real-world problems is what the Wyss Institute is all about," said Wyss founding director Don Ingber. "This work is a beautiful example of how bringing together scientists and engineers from multiple disciplines to carry out research inspired by nature and focused on translation can lead to major technical breakthroughs."
The full results of the research will appear in the 3 May issue of Science.