A quartet of Harvard University
reseachers have designed, manufactured, and flown a tiny, fly-inspired aerial
robot that could be the forerunner of swarms of drosophilistic drones.
To put their achievement in boffinary
terms, as did the authors in the abstract of their paper, published in the latest issue of the
jounal Science, "We developed high-power-density piezoelectric
flight muscles and a manufacturing methodology capable of rapidly prototyping
articulated, flexure-based sub-millimeter mechanisms."
And it took them a dozen years to do
it. "This is what I have been trying to do for literally the last 12
years," one of the paper's authors, engineering and applied science
professor Robert Wood, said in an announcement by Harvard's Wyss Institute for
Biologically Inspired Engineering, where the work was done.
You might reasonably ask why it took so
long. Simple: there are no off-the-shelf parts you can use to build what the
paper describes as "an 80-milligram, insect-scale, flapping-wing robot
modeled loosely on the morphology of flies." Or, as one of Wood's fellow
authors Pakpong Chirarattananon, calls it, the RoboBee.
"We had to develop solutions from
scratch, for everything," Wood said. "We would get one component
working, but when we moved onto the next, five new problems would arise. It was
a moving target."
Two of the innovations the team came up
with were a piezoelectric wing actuator and a method of laser-cutting the
RoboBee's carbon fiber and polymer film body material in such a way that it
naturally transforms from 2D to 3D much like structures in a kid's pop-up book.
"It's really only because of this
lab's recent breakthroughs in manufacturing, materials, and design that we have
even been able to try this," Wood said. "And it just worked,
spectacularly well."
As might be guessed, tolerances at this
tiny level were a bear to work out – the slightest deviations would cause
prototypes to go haywire. One of the coauthors, Kevin Ma, told ScienceNow that even if the RoboBee's wings were
the tiniest bit asymmetrical, the flying bug couldn't be controlled. But when
he finally got it right, "It was an amazing feeling of having all of this
hard work suddenly bear fruit," he said.
That was the team's "Kitty Hawk
moment," Wood recalls.
The team still has a good deal of work
to do before swarms of these little fellows can autonomously roam the skies.
For example, they still require tethering for power and control, a limitation
that may not be easily overcome.
Ma, however, is optimistic – he hopes to get
power and sensors onboard before he graduates in two years, and create a swarm
of free-flying RoboBees. ® [Source]

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