Airbags are standard in most of the cars now and while taken as a joke when they started out back in the 1970s, they have become quite effective over time and work in collaboration with the seat-belts to keep the driver and passenger safe in case of a collision. The basic idea of an airbag is that it pushes the driver back into the seat and holds them there for almost a second before the pressures subsides and the airbag deflates.
In engineering terms, the airbags basically decrease the momentum of the driver and passenger within a car to zero once there is a collision. The challenge? This stoppage has to take place in a second and the only space available is the space between driver and steering wheel. So, how do they really work?
To understand that, you need to first understand what is an airbag made of; it has three main components. They are bag, the sensor and the inflation system. Airbags are created using a very fine gauge of nylon subsequently getting folded and placed into the steering wheel, dashboard, door panel and at times the roof rails located above the door. The sensor is the mechanism that determines the right time for the bag to inflate. This process requires a force equivalent of running into a brick wall at 10-15mph. The latest sensors also determine if there is a person in the seat next to them and whether the passenger has enough weight for the bag to be deployed safely. The inflation system of the airbag is usually a mix of potassium nitrate (KNO3) and sodium azide (NaN3) which results in the formation of nitrogen gas. The hot discharging of this gas inflate the airbag at a speed of about 200mph and right after inflation, the gas gets dispersed via tiny holes in the airbag causing it to deflate. The whole process is complete in 1/25th of a second. Cornstarch along with talcum powder is used within the storage system for ensuring that the airbags remain stick-proof and flexible.
Pointers to keep in mind are as follows;
1. The ideal distance between the airbag and breastbone is 10 inches.
2. Those who are under 5’4” (adults and children) should be riding with airbags switched off to avoid any injury taking place to their head or neck during the collision.
3. Children in backward-facing infant seats must never be in the front seat while the airbag is engaged.