Images courtesy of Jacobs School of Engineering at UC San Diego.
As more and more robots make coffee, people in University of California, San Diego discover that coffee gives the robots a little more energy.
Robotics in Jacobs School of Engineering found that ground, roasted coffee is the perfect stuffing for miniature rubber boots that attach to the feet of walking robots. They act as pliant pads that allow the machines to walk up to 40% faster on uneven surfaces, such as wood chips or pointed gravel.
The goal is to aid robots function more effectively as interplanetary explorers and search-and-rescue tools while navigating unsafe disaster sites.
Each UCSD-designed robotic foot consists of an internal support structure in a pliant latex ball that is filled with loose, parched coffee grounds. The feet remain supple when lifted and moved in the air, but when pressed against the ground, they mold to the shape of whatever they step on, then stiffen in a phenomenon known as “granular jamming.”
“The basic principle is that loosely packed coffee grounds flow like a liquid but seize up like a solid when the air is removed,” study co-author and UCSD professor Nicholas Gravish told Daily Coffee News. “You can see this in action when you buy a modern pack of vacuum-sealed coffee. It feels solid, very brick-like, but when you cut it open, you can suddenly crush the back and change its shape.”
Lead author Emily Lathrop, a doctoral candidate at UCSD, will present the report, co-authored by Department of Mechanical and Aerospace Engineering professors Gravish and Michael T. Tolley. RoboSoft Conference will be held virtually this year, from May 15 to July 15.
The ground becomes solid when it is passively gripped under the robot’s weight as it walks, which helps the robots on flat surfaces. Vigorous gripping occurs on pointed and uneven surfaces, when the machines suck air out of the latex ball after it has conformed to the shape it is walking on, for sure footing as the robot moves forward. In both situations, the coffee feet give the robots better traction, greater speed and less effort when walking in challenging situations.
Coffee was a good choice for this application because it’s lithe and relatively inexpensive, Scientist says, which was especially true for the particular coffee they were using, at least in part because of its convenience. The research team loaded their robo-feet with pre-ground Folgers Classic medium-roast coffee, because that’s what they had in the lab.
Lathrop said, “Coffee is a staple of the college student diet.”
However, what makes coffee perfect is the naturally varying particle size distribution within the typically coarsely ground beverage.
Howard Bryman
Howard Bryman is the deputy editor of Daily Coffee News at Roast Magazine. He lives in Portland, Oregon.
