SFU engineering science researchers have created a robot that can scale walls with tank-like moves using an adhesive that re-creates the “sticky toes” of a gecko.

The research, published today in the IOP Publishing journal Smart Materials and Structures, provides an alternative to using magnets, suction cups or claws, which typically fail at climbing smooth surfaces like glass or plastic. It also paves the way for a range of applications, from inspecting pipes, buildings, airplanes and even nuclear power plants to employment in search and rescue operations.

Known as the Tailless Timing Belt Climbing Platform (TBCP-11), the robot can transfer from a flat surface to a wall over both inside and outside corners at speeds of up to 3.4 cm per second. It is fitted with sensors for detecting its surroundings and changing direction.

Researchers mimicked the gecko’s dry, sticky toe pads by creating an adhesive using a material called polydimethylsiloxane (PDMS), manufactured as tiny mushroomcap-like shapes measuring 17 micrometres wide by 10 micrometres high.

Tiny belts drive the robot’s tank-like moves, providing optimum mobility and expandability.

Getting the robot to climb formed the bulk of lead author Jeff Krahn’s master’s thesis. He carried out his research with Carlo Menon, assistant professor of engineering science.

“With an adequate power supply, our robot is capable of functioning fairly independently when it encounters larger-scale objects such as boxes or walls,” says Krahn. “However, we are still developing a control strategy to ensure the robot is capable of fully autonomous functionality.”

Krahn says the robot prototype uses biomimetic dry adhesives that rely on Van der Waals forces — weak but attractive forces that occur between molecules — for adhesion.

“The adhesives are composed of an array of micro-scale fibers that look similar to flat-topped mushroom caps,” says Krahn. “This design allows the fibers to conform to relatively rough surfaces, as is important for Van der Waals forces.”

The robot is unique not only for its use of dry adhesives, but because it doesn’t require a tail, as do previous tank-like robots. Instead, it uses two modules linked by an active joint to ensure contact of the adhesives.

As well, sensors detect when the robot is beginning to detach, allowing it to adjust accordingly.

Krahn, who received his Master of Applied Science at the October 2011 convocation, is now working at the university as a research assistant. He plans to pursue PhD studies at SFU next spring.