The Science of Airbags

The Science of Safety

These days, there is likely no other industry that has undergone a more rigorous overhaul, in terms of safety, than the automobile industry. As cars have gotten more sophisticated and have been outfitted with better engines that could get the car traveling at higher rates of speed, safety features have become more and more essential, as well as more standardized. 

For instance, back in the time of the Ford Model-T, cars could only reach up to 45 mph if the driver really “let loose.” A collision at that speed is still deadly, but those who drove the Model-T (at least, at first) didn’t have to share the road with many other vehicles and didn’t often have cause to run at top speed. As such, steering wheels weren’t padded, or outfitted with airbags; instead, many models had large, decorative, medal bumps in the center of the wheel. This looked nice, of course, but was also extremely dangerous if someone slammed their chest or their head into the steering wheel during a collision.

Today, we’ve wisened up about safety, thanks in large part to trial and error. We have let science be our guide to solving major problems. Airbags, especially, are an ingenious invention meant not only to keep us from smashing hard into the steering wheel but full-on careening out the windshield.  

How They Work

Unless you are a car repair specialist, you may be surprised to learn that airbag deployment is the result of a chemical reaction within the vehicle. The airbags themselves are not inflated with air or compressed gas, as one would think. Instead, a chemical called sodium azide (NaN3) is the magic agent at the center of the airbag mechanic.

• Every modern car is outfitted with sensors all over the chassis that detect a collision.
• The sensors send an electrical signal to the canisters filled with sodium azide, causing a small igniter charge to detonate.
• The ignition blast acts upon the sodium azide, making it decompose into nitrogen gas.
• The nitrogen gas fills the airbag in 0.03 seconds. 

As alluded to in the latter point, this process happens extremely fast. At 30 milliseconds, the airbag is fully inflated, which means that the entire process, from sensor warning to the collision of the driver with the airbag happens in a blindingly fast 50 milliseconds. This is why it is essential to ensure that your vehicle comes in for regular car repairs so that this process works perfectly every time.

A Bit of History

Although air-filled bags had been used in aviation since before the 1920s, the typical airbag apparatus that we know today for automobiles was patented in 1952 by John W. Hetrick. Hetrick’s airbag (as well as others that had been invented and patented at this time) used compressed air to fill the bag. Although Hetrick was a Naval engineer with vast experience in mechanical systems and building, his invention was largely overlooked by many of the car manufacturers at the time. 

Today, as we all know, airbags are required in every new make and model across the globe.

If you have been in a collision and are in need of a car repair, or you fear that your airbag may not be working correctly, stop by our South Orem Master Muffler today and we’ll make sure your car is completely road- and crash-worthy.