6 August 2009

Angle of ascent triggers gecko grip

Scientists have discovered the trigger that deploys geckos' grip adhesive. The goal of this research is to understand their complex traction system and use it for commercial applications.

Geckos are very adept at climbing through difficult terrain using an intricate adhesive system. Until now, we did not know when and how they switch on their unique system of traction. Scientists at the University of Calgary (U of C) and Clemson University in South Carolina have discovered gravity triggers the geckos’ amazing grip.

“Geckos use microscopic, hair-like filaments to attach to surfaces. Only at certain angles do they switch on their traction system, however,” said Anthony Russell, a biological sciences professor at the U of C. “We are trying to understand this process, which will help in mimicking it for application to robotics.”

Geckos have the remarkable ability to move on smooth surfaces such as glass. This study adds a new angle to previous research; geckos must be on an incline in order to trigger the deployment of their adhesive system.

The scientists discovered the tipping point, which turns on the gecko’s adhesive system, is 10 degrees. Three of the six geckos studied applied their adhesive system on a 10-degree slope. At 30 degrees, all six applied the system. The three that applied the traction at 10 degrees slowed down, the three that did not were much quicker.

For related information, go to www.isa.org/motionsystems.