A Sticky Situation: Inspired by Geckos, Metin Sitti and His Research Team are Developing Self-Cleaning Adhesives-Mechanical Engineering - Carnegie Mellon University

Tuesday, March 18, 2014

A Sticky Situation: Inspired by Geckos, Metin Sitti and His Research Team are Developing Self-Cleaning Adhesives

Inspired by geckos, Metin Sitti and his research team are developing self-cleaning adhesives — and gaining global media attention for their innovative work.
Professor Metin Sitti has always been inspired by nature in his research, which has produced swimming and swarming robots that mimic the natural movements of animals. In his most recent work, Sitti is seeking to replicate the self-cleaning properties of the sticky feet of geckos. By transferring these properties to manufactured adhesives, Sitti hopes to make them both stronger and more durable over time.

“Geckos’ feet remain clean, even in dirty and dusty environments, because their mushroom-shaped hairs help shed contaminants with every step,” explains Sitti. “In the lab, my team has tried to copy these characteristics using mushroom-shaped elastomer fibers and spherical silica contaminants. Using a load-drag-unload cleaning process similar to the loads acting on the gecko’s foot during climbing, our fully contaminated synthetic adhesives recovered lost stickiness at a rate comparable with that of the gecko.”

The March 12 edition of Newsweek features an article on Sitti’s breakthrough, called “Tape Inspired by Geckos Is Crazy Strong and Cleans Itself.” A paper based on this research — called “Staying Sticky: Contact Self-Cleaning of Gecko-Inspired Adhesives” — was published on February 19 in Interface Focus, the Royal Society’s cross-disciplinary themed publication that highlights research at the interface between the physical and life sciences.
Sitti and Uyiosa Abusomwan, a MechE doctoral student, also won first prize at the Adhesion Society Conference on February 26 for their poster on this research, entitled “Particle Rolling on a Gecko-Inspired Microfiber Adhesive Interface.”

In addition to Abusomwan, Sitti’s research team includes MechE doctoral student Yigit Menguc, as well as Hendrik Hoefscher and Michael Rohrig of Karlsruhe Institute of Technology in Germany. Their work is funded by the Civil, Mechanical, and Manufacturing Innovation Division of the National Science Foundation.
“Our research has a range of potential applications in a variety of industry sectors, including defense, consumer products, sporting goods, automobiles, medicine, aerospace and robotics,” Sitti said. “Contamination of adhesives is a common problem that affects their ability to perform at an optimal level over time.”
In 2009, Sitti founded a spin-off company, nanoGriptech, Inc., to help commercialize his gecko-inspired adhesives. Today, he and his team are also developing new methods to print electronics on complex surfaces, using reversible adhesives that can attach electronics to clothing, plastic, and leather. This innovative work also focuses on gaining new control of adhesion strength.

Sitti, who joined MechE in 2002, was recently inducted as a Fellow of the Institute of Electrical and Electronics Engineers (IEEE). He has won a number of awards, including the National Science Foundation CAREER Award as a junior faculty member in 2005. His NanoRobotics Lab in MechE employs 15 to 20 doctoral and post-doctoral student researchers. Sitti’s groundbreaking research has been financially supported by NSF, the National Institutes of Health (NIH), NASA, the Department of Defense (DoD), and corporate sponsors.