Inspired by geckos clinging to sheer, vertical surfaces, scientists developed a similar adhesion mechanism that allowed a human to scale a glass wall.
"Just as natural gecko adhesives have been used as a benchmark for synthetic materials, so can gecko adhesion systems provide a baseline for scaling efficiency," the Stanford University researchers wrote in the abstract of their study published in the Journal of the Royal Society Interface this week.
The team created a "synthetic adhesion system" using "gecko-inspired" principles that allowed a 159-pound man to climb a vertical wall. They were especially pleased that the "system does not fail catastrophically when a simulated failure is induced on a portion of the adhesive."
Earlier this year, DARPA, the military's research arm, announced that it created a system that allowed a 218-pound person to successfully climb a 25-foot glass wall with nothing but "pair of hand-held, gecko-inspired paddles."
"The gecko is one of the champion climbers in the Animal Kingdom, so it was natural for DARPA to look to it for inspiration in overcoming some of the maneuver challenges that U.S. forces face in urban environments,” Dr. Matt Goodman, DARPA's program manager for Z-Man, said in a statement. “Like many of the capabilities that the Department of Defense pursues, we saw with vertical climbing that nature had long since evolved the means to efficiently achieve it. The challenge to our performer team was to understand the biology and physics in play when geckos climb and then reverse-engineer those dynamics into an artificial system for use by humans.”
But, as MIT's Technology Review pointed out, DARPA didn't reveal details on how the system worked at the time. The Stanford team, which also worked with the Z-man project, did provide details of its similar experiment. Here's how Technology Review described it:
To make the climbing system, the researchers started with an existing adhesive based on molded microwedges made from a polymer material called PDMS. They attached tiles of this material to a flat, hexagonal, hand-sized gripper. Each gripper was backed with a spring that distributed weight across the pad, and absorbed some of the force involved in climbing. To make climbing easier, the researchers also linked the grippers to platform for a person’s feet, thereby transferring the work of climbing to the legs.
Watch this video of the experiment from the Guardian:
Last year, we saw a similar wall-scaling device that used vacuum technology.