Super adhesive material takes inspiration from nature

The Geckskin device measures about 16in and according to the researchers can hold a maximum force of about 700lb while adhering to a smooth surface such as glass. "Amazingly, gecko feet can be applied and disengaged with ease, and with no sticky residue remaining on the surface," said biologist Duncan Irschick. "These properties, high capacity, reversibility and dry adhesion offer a tantalising 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." Beyond its sticking ability, Irschick says the device can be released with negligible effort and reused many times with no loss of effectiveness. "For example," he notes, "it can be used to stick a 42in television to a wall, released with a gentle tug and restuck to another surface as many times as needed, leaving no residue." While previous efforts to synthesise the tremendous adhesive power of gecko feet and pads were based on the qualities of microscopic hairs on their toes called setae, attempts to translate them to larger scales were unsuccessful. Now, the researchers have been able to demonstrate that setae are not required for gecko-like performance. "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," Irschick says. The key innovation was said to be the creation of an integrated adhesive with a soft pad woven into a stiff fabric, which allowed the pad to drape over a surface to maximize contact. As in natural gecko feet, the skin was woven into a synthetic tendon, yielding a design that could maintain stiffness and rotational freedom. "Importantly, the Geckskin's adhesive pad uses simple everyday materials such as polydimethylsiloxane, which holds promise for developing an inexpensive, strong and durable dry adhesive," Irschick concluded. "Our design for Geckskin shows the true integrative power of evolution for inspiring synthetic design that can ultimately aid humans in many ways."