Tag Archives: Robert Full

Gecko-like toes needed for climbing robots

Caption: The spotted belly of a Tokay gecko used by UC Berkeley biologists to understand how the animal’s five sticky toes help it climb on many types of surface. Credit: Yi Song

Those are fabulous toes. Geckos and the fine hairs on their toes have been of great interest to researchers looking to increase qualities of adhesion for all kinds of purposes including for robots that climb. The latest foray into the research suggests that it’s not just the fine hairs found on gecko toes that are important.

A May 8, 2020 news item on ScienceDaily makes the proclamation,

Robots with toes? Experiments suggest that climbing robots could benefit from having flexible, hairy toes, like those of geckos, that can adjust quickly to accommodate shifting weight and slippery surfaces.

Biologists from the University of California, Berkeley, and Nanjing University of Aeronautics and Astronautics observed geckos running horizontally along walls to learn how they use their five toes to compensate for different types of surfaces without slowing down.

Close-up look at the toe pads of a Tokay gecko. They have about 15,000 hairs per foot, each of which has split ends that maximize contact with the surface and support the animal’s weight by interacting with surface molecules via van der Waals forces. (Photo by Yi Song)

You can find that image and more embedded in the May 8, 2020 University of California at Berkeley news release (also on EurekAlert) by Robert Sanders. The news release delves further into the work

“The research helped answer a fundamental question: Why have many toes?” said Robert Full, UC Berkeley professor of integrative biology.

As his previous research showed, geckos’ toes can stick to the smoothest surfaces through the use of intermolecular forces, and uncurl and peel in milliseconds. Their toes have up to 15,000 hairs per foot, and each hair has “an awful case of split ends, with as many as a thousand nano-sized tips that allow close surface contact,” he said.

These discoveries have spawned research on new types of adhesives that use intermolecular forces, or van der Waals forces, to stick almost anywhere, even underwater.

One puzzle, he said, is that gecko toes only stick in one direction. They grab when pulled in one direction, but release when peeled in the opposite direction. Yet, geckos move agilely in any orientation.

To determine how geckos have learned to deal with shifting forces as they move on different surfaces, Yi Song, a UC Berkeley visiting student from Nanjing, China, ran geckos sideways along a vertical wall while making high-speed video recordings to show the orientation of their toes. The sideways movement allowed him to distinguish downward gravity from forward running forces to best test the idea of toe compensation.

Using a technique called frustrated total internal reflection, Song, also measured the area of contact of each toe. The technique made the toes light up when they touched a surface.

To the researcher’s surprise, geckos ran sideways just as fast as they climbed upward, easily and quickly realigning their toes against gravity. The toes of the front and hind top feet during sideways wall-running shifted upward and acted just like toes of the front feet during climbing.

To further explore the value of adjustable toes, researchers added slippery patches and strips, as well as irregular surfaces. To deal with these hazards, geckos took advantage of having multiple, soft toes. The redundancy allowed toes that still had contact with the surface to reorient and distribute the load, while the softness let them conform to rough surfaces.

“Toes allowed agile locomotion by distributing control among multiple, compliant, redundant structures that mitigate the risks of moving on challenging terrain,” Full said. “Distributed control shows how biological adhesion can be deployed more effectively and offers design ideas for new robot feet, novel grippers and unique manipulators.”

The team, which also includes Zhendong Dai and Zhouyi Wang of the College of Mechanical and Electrical Engineering at Nanjing University of Aeronautics and Astronautics, published its findings this week in the journal Proceedings of the Royal Society B.

Here’s a link to and a citation for the paper,

Role of multiple, adjustable toes in distributed control shown by sideways wall-running in geckos by Yi Song, Zhendong Dai, Zhouyi Wang, and Robert J. Full. Proceedings of the Royal Society B; Biological Sciences 29 April 2020 Volume 287Issue 1926 DOI: https://doi.org/10.1098/rspb.2020.0123 Published [online]:06 May 2020

This paper is open access.

Kayaks, communication by bacteria, wind power, and biomimcry at TED 2014′s All Stars session 1: Planet Dearth

These are short talks (shorter than the 18 min. TED talk).  Wish I could cover everyone but I’m beginning to tire so I’ve started with George Dyson, historian of science, from his TED biography,

In telling stories of technologies and the individuals who created them, George Dyson takes a clear-eyed view of our scientific past — while illuminating what lies ahead.

Dyson described Vancouver of 16,000 years ago under an ice sheet and then 10,000 years ago people showed up. 5000 years ago the rainforest emerged and became the setting for a culture and society unique in the world. Most traces of that culture are gone.  Dyson then segued into a description of his love for kayaks and how he arrived in Vancouver at age 17 (19?). He now lives in Washington state. He wants to suggest that commercial sail will return or as they are saying in this session, become ‘de-extinct’.

Then there was Bonnie Bassler, molecular biologist, from her TED biography,

Bonnie Bassler studies how bacteria can communicate with one another, through chemical signals, to act as a unit. Her work could pave the way for new, more potent medicine.

She talked about quorum sensing (chemical communication), the means by which bacteria communicate with each other. They in Bassler’s lab can change the molecule which signals quorum sensing the means by which bacteria communicate to create biofilm, a precursor to toxin secretion and infection. (I forget which disease she mentioned) By changing the molecule they can stop the process in the laboratory. You can find out more about bacteria and quorum sensing here.

Next, there was Amory Lovins, physicist and energy guru, from his TED biography (Note: A link has been removed),

Amory Lovins was worried (and writing) about energy long before global warming was making the front — or even back — page of newspapers. Since studying at Harvard and Oxford in the 1960s, he’s written dozens of books, and initiated ambitious projects — cofounding the influential, environment-focused Rocky Mountain Institute; prototyping the ultra-efficient Hypercar — to focus the world’s attention on alternative approaches to energy and transportation.

He talked about wind and solar power and mass production of equipment to produce this energy. He debunked the notion that alternatives such as wind and solar power are not dependable sources by citing statistics from France showing that they can predict how energy is needed and can be produced in situations of uncertainty.

Finally, Robert Full, biologist, from his TED biography,

Robert Full studies cockroach legs and gecko feet. His research is helping build the perfect “distributed foot” for tomorrow’s robots, based on evolution’s ancient engineering.

Difference between human and nature’s design is robustness, i.e., able to adapt to changing terrain and use same structures for different tasks. He also mentions fault tolerance, i.e., change in a structure does not have to unduly affect the animal/insect, e.g., a  cockroach has an alternative means of achieving the same ends, e.g. walking without feet. Full’s conclusion is that you never know where curiosity-driven research will take you as he mentions the possibility of cockroach-inspired robots while showing scenes of disaster (building rubble) where a suit based on an insect exoskeleton which survives compression could be very handy.