Velcro fasteners

Consider the story of George de Mestral, a Swiss inventor who went
hunting one day in the late 1940s. He and his dog accidentally brushed
up against a bush that left them both covered with burrs.

When de Mestral tried to remove the burrs, they clung stubbornly to his clothes.
This would be a minor annoyance to most of us, but de Mestral was
curious about why the burrs were so hard to remove. After he got home,
he studied them under a microscope and discovered that hundreds of
tiny hooks on each burr had snagged to the threads of his pants. Burrs,
he thought, would make great fasteners.
After several years of work, he finally succeeded. The result: Velcro
fasteners, now used on millions of items, from blood pressure cuffs to
tennis shoes.