A Look at the Science that Makes Airbags Deploy so Fast
November 4th, 2009The airbag design is nothing new, and some people may be astounded to realise the design has been in existence for over sixty years. The very first patent on an air bag for aeroplanes was submitted during World War 2. In the 1980s, the first commercial airbags were a safety feature in cars.
Right up to today, statistics reveal that airbags reduce the chance of death in a square anterior crash by around 30%. Nowadays we also have seat-mounted and door mounted side airbags. In fact, some cars go far beyond only having twin airbags, and instead have six to eight airbags.
The job of an air bag is to ease the driver’s forward motion as evenly as possible in just a fraction of a second. There are 3 parts to an airbag that help execute this task:
- The airbag is made of a slim, nylon fabric that’s folded into the steering wheel or dashboard and, more recently, the seat or door
- The detector is the gadget that orders the airbag to expand. Inflation occurs when there’s a smash force equal to running into a brick wall at 10 to 15 miles an hour. A switch is flicked when there is a mass movement that closes an electric contact, informing the detectors that a crash has taken place. The sensors receive data from an accelerometer that’s part of a silicon chip
- The airbag’s ballooning facility melds sodium azide with potassium nitrate to develop nitrogen gas. Hot gusts of the gas blow up the airbag
Due to the superfast deployment of an air bag, it’s a safety requirement that the driver and passenger sit in the seat with a straight back leaving a safe distance between their face and the dashboard / steering wheel – this sets aside time for the bag to deploy while the driver/passenger are being forced forwards by the affect of the crash.
