The Airbag (1951)
John Hetrick is responsible for the creation of the airbag. He got in a car crash with his wife and daughter and they had to hold his daughter back so she wouldn't fly into the dashboard. He then thought "Why isn't there something to prevent this from happening?" and so he decided to create the airbag.
Airbags are designed to prevent head, chest, and other severe injuries during a car collision. It is designed so it inflates in less than a second, serving as a cushion preventing the head and chest from hitting the hard surfaces in a car.
Airbags are still used today and every car put onto the market has airbags installed. Airbags are even found in the seats on airplanes.
When a car decelerates very quickly due to a crash, an accelerometer (electronic chip that measures acceleration and force) detects the change of speed. If the deceleration is great enough the airbag circuit is triggered. The airbag circuit passes an electric current through a heating element which then ignites a chemical explosive. As the explosive burns it generates a massive amount of harmless gas that floods into a bag behind the steering wheel. When the bag expands it blows off the cover of the steering wheel and inflates in front of the driver. When the body of the driver presses against the airbag it causes the gases to be pushed out and the bag to deflate.