Vending machine slug rejector

The invention: 

A device that separates real coins from counterfeits,
the slug rejector made it possible for coin-operated vending
machines to become an important marketing tool for many
products .

Velcro

The invention: 

A material comprising millions of tiny hooks and
loops that work together to create powerful and easy-to-use fasteners
for a wide range of applications.

The person behind the invention:

Georges de Mestral (1904-1990), a Swiss engineer and inventor

Vat dye

The invention:

The culmination of centuries of efforts to mimic the
brilliant colors displayed in nature in dyes that can be used in
many products.

The people behind the invention:

Sir William Henry Perkin (1838-1907), an English student in
Hofmann’s laboratory
René Bohn (1862-1922), a synthetic organic chemist
Karl Heumann (1850-1894), a German chemist who taught Bohn
Roland Scholl (1865-1945), a Swiss chemist who established the
correct structure of Bohn’s dye
August Wilhelm von Hofmann (1818-1892), an organic chemist