CMU professor's super adhesive inspired by the gecko

| Saturday, Sept. 12, 2009

Prior to becoming the British-accented spokesman for Geico insurance and dancing mascot for SoBe beverages, the gecko was an ordinary creature, found locally in Western Pennsylvania zoos and pet stores.

Scientists for years have been fascinated with the animal, not because of its accent or dance-floor moves, but because of its toes. The billions of hairs on the gecko's toes give the animal the gravity-defying ability to climb the smoothest of surfaces, vertical or horizontal, and to be able to hang by even a single toe, if needed.

Carnegie Mellon University Associate Professor of Mechanical Engineering Metin Sitti is an authority on what he calls the gecko's "one-sided Velcro" adhesive ability.

"It's not like glue, it's not a liquid, it's a temporary attachment," said Sitti, who is head of the university's NanoRobotics Laboratory and is on the faculty of CMU's Robotics Institute.

In January, Sitti was confident enough in his research and findings that he formed nanoGriptech LLC, hoping to commercialize the gecko's adhesive ability. In just nine months, the fledgling company has received $450,000 in funding from the Department of Defense and the National Science Foundation, along with Air Force Research Laboratory funds funneled through the Pennsylvania NanoMaterials Commercialization Center.

Sitti says a gecko's toes have millions of very small hairs, each one-tenth the width of a human hair. At the end of each hair are hundreds of saucerlike structures known as spatula, each 500 to 1,000 times smaller than a human hair's width.

Weak forces of attraction hold each spatula to a surface, but when the weak force from millions of hairs are combined, a powerful bond is created, allowing the gecko to stick to nearly anything.

Sitti uses microfabrication, manufacturing on an ultra-small scale to create mold templates, which are filled with polymers to create the hair-like appendages. To make the spatula, a drop of polymer is placed on a fiber, then pressed to a nonstick surface, followed by curing the tip.

Starting at the University of California-Berkeley and continuing when he joined the CMU faculty in 2002, Sitti has been working to replicate the gecko-like adhesive in the laboratory and commercialize it.

"We've been in business about three years and during that time, we've had about 75 proposals for funding and awarded about 14," said Alan Brown, the NanoMaterials Commercialization Center's director. "Our criteria is a technology must be unique and there must be a market for product applications. This is a great idea, it's patentable and it has those partners."

One partner is Bayer MaterialScience LLC, which provides the substance that makes the pseudo-Gecko-hairs adhesive work.

"We were introduced to Dr. Sitti through our new business group, which identifies and creates new business opportunities beyond our existing portfolio of products," said Karsten Danielmeier, vice president Business Development, Coatings, Adhesives and Specialties for Bayer MaterialScience.

Danielmeier said Bayer was looking at the super adhesive to give robots the ability to climb over any obstacle to fulfill its particular mission.

Mine Safety Appliances Co. of O'Hara is working with Sitti on developing his adhesive for face mask sealant applications.

Sitti refused to reveal the name of his third partner, but a news release from the state's Innovation Partnership said Baltimore-based clothing manufacturer Under Armour Inc. is interested in the adhesive for fastening gloves, shoes, and clothing. A spokesman for the publicly-held company couldn't be reached.

Sitti said his product can be used anywhere Velcro is pressed into action. Unlike Velcro, which requires two cloth pieces, one comprised of very small hooks and other surface made of clinging pile, the nanoGriptech adhesive is a single surface.

While just getting nanoGriptech off the ground, with office space in Oakland and three to five of his students serving as original employees, Sitti intends to keep the company in Pittsburgh.

"I am in the first stage of commercialization, prototyping specific product applications with our partners," Sitti said. "After this stage is completed, in one or two years, we will move toward large-scale manufacturing." He added that about 5,000 square feet of space is needed for large-scale manufacturing of the super adhesive.

"The company will be focused on the design and manufacture of the adhesive, and we want to make sure the company will make products here and sell them here," Sitti said.

Subscribe today! Click here for our subscription offers.


Show commenting policy