by To give grasshoppers some credit—jumping across yards and between branches takes a lot more expertise than meets the eye. There are incredibly tiny factors to consider, such as resistance to the launch surface material (Are the blades of grass bouncing? Is the plant branch fragile?), as well as your desired distance, speed and landing.
Most jumping robots cannot compete with the insect, as their jumps are limited to launching over extremely rigid surfaces. But a new bot developed by researchers at Carnegie Mellon’s College of Engineering soars above those barriers and shows tremendous promise for how autonomous devices could work in the future.
(Related: Watch These Tiny Bugs Swallow Urine With Their Butts.)
A team of scientists led by mechanical engineering professor Sarah Bergbreiter recently optimized a robot’s locking mechanisms used to propel it upward. Previously, these latches were primarily thought of as simple “on/off” switches that allowed the release of stored energy. However, Bergbreiter and her team used mathematical modeling to show that these latches were capable of directing energy production, as well as controlling energy transfer between the jumper and the launch surface.
To test their work, the team placed a small robot jumping over a tree branch and recorded the precise energy transfers in the first moments of its jumps. By watching the branch retract before the robot jumped, they could tell that the device was recapturing at least some of the energy that was initially transferred to the branch just before takeoff.
“We found that not only can the latch mediate energy production, but it can also mediate energy transfer between the jumper and the environment from which it jumps,” Bergbreiter said.
The researchers also observed an “unconventional” energy recovery in other cases that used a different variety of latching. In these cases, the branch actually provided a small boost to the bot after it jumped off its surface, thus returning some of its momentum to propel it higher.
(Related: This tiny robot grips like a gecko and squirms like a worm.)
Now that researchers have a better understanding of the interactions at play in the first moments of the jump, they can now begin working on ways to incorporate it into future robotic designs. Likewise, biologists can gain a better understanding of how insects maneuver in variable terrain, such as grass or sand.
“It was almost impossible to design controllable insect-sized robots because they launch in just milliseconds,” explained Bergbreiter. “Now, we have more control over whether our robots jump up with one leg or three… It’s really exciting that the latch – something we already need in our robots – can be used to control outputs that we couldn’t control before. “
