AMHERST, Mass. – Geckskin, a super-
strong adhesive device developed by University of Massachusetts Amherst researchers that can hold 700 pounds on a smooth wall, has been named one of the top five science breakthroughs of 2012 by CNN Money.
Inspired by the footpads of geckos, Geckskin was created by Michael Bartlett, a doctoral candidate in polymer science and engineering, polymer scientist Alfred Crosby and biologist Duncan Irschick, who has studied the gecko’s climbing and clinging abilities for more than 20 years. The researchers published their findings in the journal Advanced Materials last February.
“Amazingly, gecko feet can be applied and disengaged with ease, and with no sticky residue remaining on the surface,” Irschick said at the time their study was released. These properties, high-capacity, reversibility and dry adhesion offer a tantalizing possibility for synthetic materials that can easily attach and detach heavy everyday objects such as televisions or computers to walls, as well as medical and industrial applications, among others, according to the scientists.
While the research was funded by the U.S. Defense Advanced Research Projects Agency (DARPA), known for developing high-tech espionage and warfare gadgets, CNN Money notes that “Geckskin could have more immediate uses for your everyday non-spy.”
Michael Tomczyk, managing director at Wharton’s Mack Center for Technological Innovation, told CNN Money, “This is cool not just because it is quirky and functional but because this is an early signal of things to come. In the next few years, we will see more examples of commercial products and applications that replicate nature.”
Previous efforts to synthesize the tremendous adhesive power of gecko feet and pads were based on the qualities of microscopic hairs on their toes called setae, but efforts to translate them to larger scales were unsuccessful, in part because the complexity of the entire gecko foot was not taken into account. As Irschick explained, a gecko’s foot has several interacting elements, including tendons, bones and skin, that work together to produce easily reversible adhesion.
Irschick, Bartlett, Crosby and the rest of the UMass Amherst team unlocked the simple yet elegant secret of how it’s done, to create a device that can handle excessively large weights. Geckskin and its supporting theory demonstrate that setae are not required for gecko-like performance, according to Crosby. “It’s a concept that has not been considered in other design strategies and one that may open up new research avenues in gecko-like adhesion in the future.”
The key innovation by Bartlett and colleagues was to create an integrated adhesive with a soft pad woven into a stiff fabric, which allows the pad to “drape” over a surface to maximize contact. Further, as in natural gecko feet, the skin is woven into a synthetic “tendon,” yielding a design that plays a key role in maintaining stiffness and rotational freedom, the researchers explain.
According to Crosby, “Our Geckskin device is about 16 square inches, about the size of an index card, and can hold a maximum force of about 700 pounds while adhering to a smooth surface such as glass.”
Beyond its impressive sticking ability, the device can be released with negligible effort and reused many times with no loss of effectiveness. For example, it can be used to stick a 42-inch television to a wall, released with a gentle tug and restuck to another surface as many times as needed, leaving no residue.
The UMass Amherst researchers are continuing to improve their Geckskin design by drawing on lessons from the evolution of gecko feet, which show remarkable variation in anatomy. “Our design for Geckskin shows the true integrative power of evolution for inspiring synthetic design that can ultimately aid humans in many ways,” said Irschick.