“They can do parallel science with a rover, so you can increase the amount you’re doing in a day,” said Jaakko Karras, PUFFER’s project manager at JPL. “We can see these being used in hard-to-reach locations, squeezing under ledges, for example.”
The team developing PUFFER at JPL hope to see the robot rolling across the surface of Mars someday. Scientists who do fieldwork on Earth also see potential in the backpack-ready robot.
“Having something that’s as portable as a compass or a rock hammer means you can do science on the fly,” said Carolyn Parcheta, a JPL scientist who uses robots to explore volcanoes.
PUFFER’s body was designed by Karras, who was experimenting with origami designs. Karras worked on developing robotics based on natural forms, such as the movement of insects and animals, as a grad student at UC Berkeley’s Biometric Millisystem Lab. The PUFFER team substituted paper with a printed circuit board, allowing them to incorporate more electronics, including control and simple instruments.
“The circuit board includes both the electronics and the body, which allows it to be a lot more compact,” said Christine Fuller, a JPL mechanical engineer who worked on PUFFER’s structure and tested it for reliability. “There are no mounting fasteners or other parts to deal with. Everything is integrated to begin with.”
The original prototype was little more than rolling origami, with four 3-D printed wheels, but later designs became more complex. PUFFER now has two wheels instead of four and a tail was added for stabilization. The new wheels have treads which help the robot climb inclines. The wheels can also be folded over the main body, allowing PUFFER to crawl. PUFFER can also flip over and recharge in sunlight using solar panels on its belly.
The PUFFER team partnered will the Biometric Millisystem Lab, which developed a “skittering walk” that keeps the bot inching forward, one wheel at a time, without slipping. A company called Distant Focus Corporation, Champaign, Illinois, provided a high-resolution microimager sensitive enough to see objects that are just 10 microns in size, a fraction of the diameter of a human hair.
Once the PUFFER team had a functional prototype, they took it out for field testing in Rainbow Basin, California, where the robot clambered over sedimentary rock slopes and crawled under overhangs. The desert terrain serves as an analog to the Martian surface. Overhangs on Mars could be sheltering organic molecules from harmful radiation. Darkly colored Martian slopes are another potential target of interest to scientists. On a level dirt path, PUFFER can drive about 2,050 feet (625 meters) on a single battery charge. That distance could vary slightly depending on how much any instrument are used.
In addition to its desert trials, PUFFER has also been tested in wintry conditions. JPL’s Kalind Carpenter, who specializes in robotic mobility, designed larger wheels and a flat fishtail to help the robot traverse snowy terrain. The robot has been tested at a ski resort in Grand Junction, Colorado, Big Bear, California and on Mt. Erebus, an active volcano in Antarctica.
The JPL team is working to add a number of scientific instruments to PUFFER, including a spectrometer to study the chemical makeup of its environment and instruments that would allow the robot to sample water for organic materials. Right now, the robot is controlled remotely using Bluetooth, but the team would like to add autonomy, allowing a swarm of PUFFERs to conduct science as a team.
“Small robotic explorers like PUFFER could change the way we do science on Mars,” Karras said. “Like Sojourner before it, we think it’s an exciting advance in robotic design.”
Video courtesy of NASA/JPL