Stephanie Kwolek invented Kevlar by accident while looking for a lighter tire fiber at DuPont in 1965

Velcro was inspired by burrs sticking to a dog's fur

Velcro inspired by burrs; invented by George de Mestral in 1941

Bubble Wrap (brand)

Bubble wrap, invented as wallpaper, failed; later became successful packaging material

Fax

Fax machine invented in 1843, 33 years before the telephone

Barbara McClintock

Barbara McClintock discovered transposons in maize

Microwave oven

Percy Spencer invented the microwave oven accidentally

Discovery of penicillin

Alexander Fleming discovered penicillin by accident in 1928