Tag Archives: Stickybot

Gecko-type robots and Simon Fraser University

I had to watch the (40 sec.) video a couple times to better marvel at the ‘gecko robot’ that a team of researchers at Simon Fraser University (Vancouver, Canada) have developed.

Here’s a little more information from the Nov. 2, 2011 posting by GrrlScientist on her Punctuated Equilibrium blog at the Guardian science blogs site,

Geckos are amazing animals for so many reasons, but their ability to climb glass windows is especially amazing since their sticky toes are not at all moist, as one would expect. Instead, gecko toes are dry, their adhesive ability the result of van der Waals forces. These are very weak, attractive forces that occur between molecules. For this reason, the gecko’s dry but sticky toe pads have long inspired scientists and engineers, especially mechanical engineers trying to design wall-climbing robots.

It looks like someone has finally succeeded. According to a hot-off-the-presses paper, a group of researchers from Simon Fraser University in British Columbia, Canada, have finally developed a robot – nowhere near as elegant in form as a gecko – that has the gecko’s ability to scale smooth walls and shuffle across ceilings without crashing down onto anyone’s head.

Here are some more details about the technology and the researchers (from the Nov. 1, 2011 SFU media release),

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 robot’s tank-like moves, providing optimum mobility and expandability.

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

This is the smoothest, most efficient climbing robot (stickybot) that I’ve seen. My August 26, 2011 posting featured  stickybots (with video) from  researchers at Stanford University.

Stickybots at Stanford University

I’ve been intrigued by ‘gecko technology’ or ‘spiderman technology’ since I first started investigating nanotechnology about four years ago.  This is the first time I’ve seen theory put into practice. From the news item on Nanowerk,

Mark Cutkosky, the lead designer of the Stickybot, a professor of mechanical engineering and co-director of the Center for Design Research [Stanford University], has been collaborating with scientists around the nation for the last five years to build climbing robots.

After designing a robot that could conquer rough vertical surfaces such as brick walls and concrete, Cutkosky moved on to smooth surfaces such as glass and metal. He turned to the gecko for ideas.

“Unless you use suction cups, which are kind of slow and inefficient, the other solution out there is to use dry adhesion, which is the technique the gecko uses,” Cutkosky said.

Here’s a video of Stanford’s Stickybot in  action (from the Stanford University News website),

As Cutkosky goes on to explain in the news item,

The interaction between the molecules of gecko toe hair and the wall is a molecular attraction called van der Waals force. A gecko can hang and support its whole weight on one toe by placing it on the glass and then pulling it back. It only sticks when you pull in one direction – their toes are a kind of one-way adhesive, Cutkosky said.

“Other adhesives are sort of like walking around with chewing gum on your feet: You have to press it into the surface and then you have to work to pull it off. But with directional adhesion, it’s almost like you can sort of hook and unhook yourself from the surface,” Cutkosky said.

After the breakthrough insight that direction matters, Cutkosky and his team began asking how to build artificial materials for robots that create the same effect. They came up with a rubber-like material with tiny polymer hairs made from a micro-scale mold.

The designers attach a layer of adhesive cut to the shape of Stickybot’s four feet, which are about the size of a child’s hand. As it steadily moves up the wall, the robot peels and sticks its feet to the surface with ease, resembling a mechanical lizard.

The newest versions of the adhesive, developed in 2009, have a two-layer system, similar to the gecko’s lamellae and setae. The “hairs” are even smaller than the ones on the first version – about 20 micrometers wide, which is five times thinner than a human hair. These versions support higher loads and allow Stickybot to climb surfaces such as wood paneling, painted metal and glass.

The material is strong and reusable, and leaves behind no residue or damage. Robots that scale vertical walls could be useful for accessing dangerous or hard to reach places.

The research team’s paper, Effect of fibril shape on adhesive properties, was published online Aug. 2, 2010 in Applied Physics Letter.