A fastener with a microscopic mushroom design holds promise

WASHINGTON, January 19, 2021 – A Velcro-like fastener with a microscopic design resembling tiny mushrooms could mean advances for everyday users and scientific fields such as robots.

In Biointerphases, published by AIP Publishing, researchers from Wageningen University in the Netherlands show how the design can use softer materials and still be strong enough to work.

Probabilistic fasteners work, because they are designed with a tiny pattern on one surface that connects to features on the other surface. Currently available fasteners are called hook and bend fasteners, such as Velcro and 3M. That design requires a harder, harder material, which is what causes the loud ripping sound when peeled off and why they could damage a fine surface, such as clothing, when to which they are attached.

The team believes that 3D mushroom design can be done with softer and more flexible materials. The semi-spherical mushroom shapes provide enough interlocking strength on the fabric and keep it strong.

For the study, the authors used 3D printing in conjunction with a mold to create a soft surface with a pattern of the tiny mushrooms. That material was then securely tied with three different clothes and removed without damaging them.

“We wanted to prove, if you go to the less strong features, they can be used to bond and tie a soft and delicate surface, like clothes, without damage. It can be used in many applications such as for diapers or silent fasteners for military use, “said author Preeti Sharma. “There’s still a lot of research to be done, but the mushroom-shaped design worked well for soft mechanical fasteners.”

The design could lead to advances in the field of soft robots. Soft robots aim to build robots with a design that resembles living creatures such as octopuses, caterpillars and worms.

In these types of robotics, the interface plays an important role. With advances that make the custom mushroom design stronger but keep it so soft, it could be used to help robots walk on walls and ceilings like a gecko – an animal that can do that on due to a bonding process that is similar to how probabilistic fasteners work.

The design could also be used on grippers for robots used in farming and other agricultural jobs, Sharma said.

Sharma said the design needs more research before it is ready for use in a commercially available product. Small changes in the shape of a mushroom, perhaps extended or shortened to make it more efficient, could get a better result, she said.

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The article “Hooked on mushrooms: The preparation and mechanics of a soft probabilistic fastener” is written by Preeti Sharma, Vittorio Saggiomo, Vincent van der Doef, Marleen Kamperman, and Joshua Dijksman. The article appears in Biointerphases on January 19, 2021 (DOI: 10.1116 / 6.0000634) and can be accessed at https: //aip.scitation.org /doi /10.1116 /6.0000634.

Biointerphases, an AVS journal published by AIP Publishing, emphasizes the quantitative character of biomaterials and biological interfaces. As an interdisciplinary journal, a strong foundation of chemistry, physics, biology, engineering, theory, and / or modeling is incorporated into original articles, reviews, and thesis essays. See https: //avs.scitation.org /magazine /bip.

AVS is an interdisciplinary, professional association with approximately 4,500 members worldwide. Founded in 1953, AVS holds local and international meetings, publishes four journals, serves members through awards, training and career services programs and supports networking among academic, business professionals. , government and consultation. Its members come from across the fields of chemistry, physics, biology, mathematics, engineering and industry and have a common interest in basic science, technology development and commercialization related to materials, interface, and processing. .