SFU Researchers Create Gecko-like Climbing Robot Using Dry Adhesive

Researchers at Simon Fraser University have created a robot with the ability to scale walls with tank-like moves using an adhesive that re-creates the "sticky toes" of a gecko.

The research, published 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 that allow it to detect its surroundings and change direction.

Researchers mimicked the "dry, sticky toe pads" of the gecko by creating an adhesive using a material called polydimethylsiloxane (PDMS) manufactured as tiny mushroom cap-like shapes that are 17 micrometres wide by 10 micrometres high.

Meanwhile, tiny belts drive the robots tank-like moves, providing optimum mobility and expandability.

Lead author Jeff Krahns work on getting the robot to climb formed the bulk of his masters thesis. The research was carried out together with engineering science assistant professor Carlo Menon.

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

Krahn says the robot, still in the prototype stage, utilizes 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 fibres which look similar to flat-topped mushroom caps. This design allows the fibres to conform to relatively rough surfaces, as is important for Van der Waals forces."

Besides using dry adhesives, the robot is unique in that instead of a tail as required by previous tank-like robots, it uses two modules linked by an active joint to ensure contact of the adhesives. Sensors were used to detect when detachment of the robot is beginning to occur and allows the robot to adjust itself accordingly.

Source: Simon Fraser University