The U.S. military has taken another major step toward turning foot soldiers into hand-over-hand wall-crawlers a la Spider-Man.
The Defense Advanced Research Projects says a 218-pound man toting a 50-pound load climbed up and down a 25-foot wall of glass using only a pair of hand-held paddles with a sticking power based on the gecko.
“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,” Matt Goodman, program manager for DARPA’S “Z-Man” project, said in a June 5 statement.
The Z-Man project includes several programs to provide combat troops Spider-Man-like climbing abilities for urban warfare. Soldiers deploying to fight in cities will have biologically inspired aids enabling them to scale vertical walls constructed from typical building materials while carrying a full combat load and without the use of ropes or ladders.
It was nearly two years ago that that the agency’s major breakthrough was a 16-square-inch sheet of material – dubbed “Geckskin” – that could stick to a vertical glass wall while supporting a static load of 660 pounds.
Geckskin is an integrated adhesive of synthetic soft skin and firm tendons that “drape” over a surface to maximize contact, the same way that a geckos feet drapes over surfaces. But just as easily as a gecko can step away from whatever surface it is climbing, the Geckskin separates from the surface with a simple tug. And, just like the gecko, it leaves behind no wet, filmy or sticky residue, officials told Defense Tech in 2012.
The novel polymer microstructure technology used in the Z-Man paddles was developed for DARPA by Draper Laboratory of Cambridge, Massachusetts, the agency said in a statement.
Humans are a lot larger and heavier than geckos, so that one of the initial challenges in developing a device to support human climbing was the issue of scaling, DARPA said in its recent statement. The Geckskin climbing paddles capable have to balance sufficient adhesive forces in both the shear (parallel to the vertical surface) and normal (perpendicular to the vertical surface) directions.
Only this way will a soldier be able to remain adhered to a surface during a hand-over-hand climb – attaching and detaching the paddles with each movement, the agency said.
