The Pentagon's top research arm has started a program called Z-Man that allows a soldier to scale vertical walls constructed from typical building materials while carrying a full load. Scientists have developed the climbing aids based on the feet of animals like geckos that are prolific climbers.
In the most recent test, a 218-pound climber carrying a 50-pound load scaled a 25-foot glass wall using only the climbing devices the engineers designed mimicking gecko's feet.
“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,” said Dr. Matt Goodman, the Defense Advanced Research Projects Agency program manager for Z-Man. "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.”
DARPA scientists recognize that there is a reason humans weren't born with gecko-like climbing abilities. For one, humans are a lot heavier, which makes it more difficult for a human to detach and reattach from a wall while bearing the weight without falling off.
Even though they are light, geckos still exert an incredible amount of adhesive pressure. Each foot has about 15-30 pounds per square inch of adhesive power. As DARPA points out, a gecko can hang off a wall using only a toe.
What gives geckos this ability are stalk-like setae in each foot. Hundreds of these setae, which act like hundreds of individual microscopic suction cups, allow the gecko to attach and reattach to surfaces with little effort.