Making Driving Safer: a Look at Air Bags
It’s a little known fact that air bags are actually not a new idea, and some people may be amazed to realise the idea has been around for over sixty years. The very first patent on an airbag for airplanes was filed during World War Two. In the 1980s, the first commercial airbags were a safety feature in vehicles.
To date, stats reveal that air bags reduce the possibility of dying in a direct head-on smash by about thirty percent. These days we also have seat mounted and door mounted side airbags. In fact, some motorcars go far beyond simply having two air bags, and alternatively have six to eight air bags.
The purpose of an air bag is to slow the passenger’s progressive motion as evenly as possible in just a fraction of a second. An air bag can accomplish this job in three steps:
- The airbag itself is composed of a slim, nylon fabric, which is packed into the dashboard or steering wheel and, these days, the seat or door
- The detector is the device that instructs the airbag to balloon. Inflation happens when there is a smash force equal to running into a brick wall at around 15 miles an hour. A switch is flicked when there’s a mass shift that closes an electrical contact, informing the sensors that a crash has taken place. The sensors receive data from an accelerometer built into a microchip
- The bag’s ballooning system melds sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas. Hot eruptions of the nitrogen inflate the airbag
Because of the superfast expansion of an air bag, it’s fundamental the driver and passenger sit in an upright position giving a safe distance between the steering wheel / dashboard and their face - this leaves time for the bag to expand while the driver/passenger are being forced forward by the shock of the accident.
