Velcro

fuckyeahphysica:

In 1941, Swiss engineer George de Mestral noticed after a
hunting trip that burrs from burdock plants stuck to his pants and his
dog’s fur

He took the seed and looked at them through a microscope to find that this seed
attaches to animal fur via the hooks on its surface to improve
distribution.

image

                               Source: All of Nature on Blogspot

These hooks would latch onto anything loop-shaped, such as the fibers in his pants and his dog’s tangled fur. This inspired him to come up with the ‘Velcro’.

Velcro is a bio-mimicry of this burrs with small flexible hooks attached on its surface to attach to fluffy surfaces.

image
image

Although it goes by the name Velcro the generic name is a  hook-and-loop fastener)  

image

And depending on the load that needs to be held there are different types of hooks that are available:

image

The sound that the velcro makes when you rip it apart is oddly satisfying. It is made when the loops are ripped apart from the hooks.

It was always in my head that the hooks or the loops would break whenever you would rip it apart. But turns out, they are extremely flexible.

image

                                                Source

For a long time I believed that this was the end of the story and that’s how far we had gone. But recently when I was trying to mount a board to the wall, I came across the 3M dual lock fasteners.

These use a mushroom shaped hook on both the sides to snap together in place.

image
image

                                                  Source

And evidently it turns out the mushroom fastener design were inspired from dragonflies who used it for stability during mating (check source video above for more).

 

This is great, but since this is made of plastic this surely would fail at higher temperatures. You need something robust to handle higher temperatures, and this is where the Metaklett comes into the picture:

image

A square metre of this fastener, called Metaklett (made of steel), is capable of supporting 35 tonnes at temperatures up to 800 ºC,  (Video)

 

There is something exotic in the blend of nature and technology that is manifested in the Velcro, I just cannot put my hand on what it is.

Have a great day!