All You Need To Know About Airbags And How They Work


There are many built-in features for safety in modern-day vehicles, ranging from seatbelts to antilock brakes, traction controls, adjustable headrests, and whatnot. All these are designed and installed in a vehicle to minimize the effects imposed by a collision or any other incident during driving. Among these features, an airbag is a major safety feature in such vehicles.

Airbags Lower the Chances of Injury

Airbags cushion the head and neck during and lower the chances of a head injury when a forward movement is experienced during a collision. The airbag comes between the passenger/driver’s head and neck and the vehicle dashboard, becoming a barrier between the two and minimizing injuries. The jolting effect occurring as a result of head repelling forward and backward sharply after contacting a fast/hard moving surface is also reduced by the airbag, hence preventing neck injuries.

But how is all this attained by the plain air-filled bag in your vehicle’s dash? It all depends on the right timing and a little explosive charge. Before looking into the details about how do airbags work, let’s look into the reason behind injuries caused by certain collisions and the role of momentum therein.


Understanding the Force Involved in an Accident

Just like almost everything around us, energy is also controlled by physics – to be more specific, the laws of motion. To understand its importance, let’s discuss mass and velocity. Mass is the amount of stuff contained in an object, closely related to the weight of an object, and is hence present in every moving object. When mass and velocity combine in an object it produces kinetic energy.

Kinetic Energy and Impact of Collision

Kinetic energy is not an issue unless the objects stop either due to collision or you stopping it deliberately. The kinetic energy built in the moving object needs to transfer itself in some other form of energy as its velocity goes to zero. Therefore, the greater the velocity, the greater the amount of kinetic energy being transformed into other forms of energy and hence, the greater damage to the vehicle and other objects nearby.

Vehicles are Designed to Absorb Maximum Impact

For this reason, most modern-day vehicles are designed such that they can absorb the maximum amount of energy when the vehicle stops moving suddenly.

This reduces the danger involved but does not take in to account the fact that the passengers and driver present in the vehicle have their own individual mass and velocity respectively. The only item present to stop the passengers and driver hitting on the front with continuous momentum is their seatbelts.

Use of Seat belts

Seatbelts have undoubtedly saved many lives, but the problem with them is that they do not provide any safety to the head and neck which are pushed forward and snapped back at a very high speed during such motion. More often, the head and neck also suffer irreparable injuries. To provide protection to these, airbags are designed which provide a cushion for the head and neck that stops them from colliding into the dash with extreme force.


How do Airbags Work?

As soon as the vehicle begins slowing down due to a collision, airbags inflate and start deflating as soon as the driver/passenger’s head comes in to contact with it. If they were not designed to deflate on contact, the issue would remain as the head would simply bounce back from its surface.

Use of Sensors and Little Explosion

This is made possible by the variety of sensors available and a little explosion. An accelerometer is featured in the airbag that detects any speed changes. If deceleration over a preset speed is detected by it, the airbag circuit is triggered.

An electric current is passed through the heating element by the circuit, igniting a chemical explosive therein. A large amount of harmless gas is generated as a result, which quickly moves in the airbag, inflating the bag placed at a space behind the passenger side dash or steering while.

As soon as the human head contacts the bag, it begins to delate as the gas starts escaping from the tiny holes around the bag’s edges. By the time the vehicle stops completely, the bag should be deflated completely.


Are Airbags Effective?

Not a Complete Solution

Airbags are not a complete solution as they are designed to work with seatbelts, therefore they must not be relied on instead of a seatbelt. It is found that airbags have reduced the fatalities due to head-on collisions by 24% when used appropriately. With the continuing improvement in vehicle safety and airbag designs specifically, the percentage is only expected to rise further.

Dangerous in Vehicles Carrying Children

Nevertheless, they must be used with the utmost care, and the use of an airbag can be somewhat dangerous in vehicles where small children are also carried. Modern-day airbags deflate with less force but rear-facing child seats should not be placed in front seats with active airbags.

Risk of Hearing Loss and Eye Injury

Moreover, there is a small risk associated with airbags for hearing loss and eye injury. The altered design of airbags has significantly reduced the number of fatalities resulting due to airbag use Accidental deaths from the use of airbags have reduced thanks to changes in the design of the airbag and improved driver education on their use. Understanding the purpose and design of airbags makes you understand why they are included in vehicles today, and why they are not deployed on every time your vehicle stops.