February 14, 2013
Robots Taking A Leap Closer To Taking Over World
Lee Rannals for redOrbit.com — Your Universe Online
The science fiction story of Isaac Asimov´s I, Robot is coming one step closer to science fact, as Harvard researchers create soft robots that can jump.
“Initially, our soft robot systems used pneumatic pressure to actuate,” said Robert Shepherd, first author of the paper, former postdoctoral researcher in the Whitesides Research Group at Harvard. “While that system worked, it was rather slow -- it took on the order of a second. Using combustion, however, allows us to actuate the robots very fast. We were able to measure the speed of the robot´s jump at 4 meters per second.”
The three-legged jumping robotic system was created by a mold developed by a 3D printer. The robots are molded using soft silicone, allowing them to stretch.
The team embedded high-voltage wires into the legs of the robots to deliver a spark, igniting a gas and causing a small explosion that sends the robot up into the air.
“We flow fuel and oxygen into the channels, and ignite it,” Shepherd said. “The heat expands the gas, causing the flap to close, pressurizing the channel and causing it to actuate. As the gas cools, the flap opens and we push the exhaust out by flowing more gas in. So we don´t need to use complex valve systems, all because we chose to mold a soft flap into the robot from the beginning.”
He said what the team was able to show was, due to the duration of the explosion, the energies absorbed by the robot are small enough to be compatible with soft robots.
"What´s more, the temperature of the robot increases by, on average, less than one kelvin," Shepherd added.
The researcher said jumping made sense as a starting point, because it released so much energy so fast. Next, he wants to learn how they can use this combustion system for other gaits, like running or even walking.
Currently, the system is limited to tethers, but one day the group hopes to bring some of our greatest fears to reality by freeing the robots from these limits.
“There´s nothing wrong with having tethered robots -- many systems used in industry are tethered,” Shepherd said in a statement. “For some search and rescue applications, however, having an untethered robot will be necessary.”
Just recently, MIT researchers began to show how a new cross training technique could be applied to teams of both robots and humans. A new algorithm designed by this team showed robots were able to work more efficiently with their human counterparts when training through cross training.