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How Airbags Work

Model: (Various brands) Various
Part: Airbag

In this video, we can see how an airbag works mechanically in the event of a collision: the impact is detected by accelerometers or gyroscopes, which measure the sudden deceleration or deformation of the bodywork. Typically, the activation threshold is 12 mph against a rigid obstacle. The system activates because the ECU sends an electrical signal to an initiator (which is a small pyrotechnic charge) that triggers a chemical reaction NaN? (sodium azide) ? Na (sodium) + N? (nitrogen gas). The nitrogen inflates the airbag in 20 milliseconds, filling a folded nylon cushion in the steering wheel or dashboard, at a temperature of 300°C (but the fabric is flame-retardant and protects against burns). The airbag deflates almost instantly to cushion the impact and prevent rebound. Simultaneously, the seatbelt pre-tensioners activate to restrain the body. All this occurs in much less than a second. Keep in mind an important detail: airbags also have an expiry date, typically after 10 to 15 years, due to the degrading charge.

Posted on 8 March 2026 by ScegliAuto

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