Airbags have two responsibilities in any vehicle. First, they slow down the sudden jerk forward movement of the passenger/driver. Second, they provide a cushioning in between the passenger’s upper body and the hard surface (dashboard, steering, windscreen, etc).
Airbags are usually fitted inside the steering wheel and dashboard. In some new makes, they are also fitted in seats and doors. We all are well aware of their importance in the wake of any high-impact collisions, but very few of us know how they really work.
Here we are going to breakdown how airbags work:
The bag is comprised of a thin and elastic nylon fabric that is folded and fixed into the steering wheel and dashboard. Nylon has the perfect combination of elasticity and strength needed for seamless bag inflation in that fraction of a moment when a collision occurs.
The sensor is the most important part of an airbag system. It actually tells the system when to inflate the bag. As per current standards, a sensor should activate the inflation system whenever there is a collision with any solid of fixed barrier between 10 to 15 mph.
The collision flips a switch that is connected to the sensor. This flipping completes an electric circuit, which is a signal for the inflation system to do its thing. Some sensors are also activated through a built-in accelerometer microchip.
3) The Inflation System
As soon as the airbag’s ignition system receives a current from the crash sensor, it sets off a chemical reaction between the stored potassium nitrate and sodium azide to produce nitrogen gas with a hot blast to inflate the nylon bag in a fraction of a second.
The ignition system bursts the solid propellant mixture to produce a large volume of gas that rips through the steering and dashboard while rapidly filling the bag. All of this happens in 1/25th of a second. After the quick inflation burst, the bag gradually deflates.
4) The Right Use of Airbags
There is a unanimous agreement on the fact that airbags can only work as life saviors when they are complemented with seat belts. A collision where the driver or passenger is not wearing a seatbelt might still result in fatal injuries despite the timely activation of airbags.
It is also important to mention here that the sudden burst of the airbag is dangerous for those who are sitting too close to the dashboard or steering. It has been estimated that a driver’s breastbone and the steering wheel should have 10 inches of distance in between them.
Airbags have saved thousands of lives in the last couple of decades by working through the simple mechanism that we have discussed here.