Researchers at the Fraunhofer Institute for High-Speed Dynamics, the Ernst-Mach-Institute (EMI) in Efringen-Kirchen, have developed a procedure by which the ignition process of an airbag can be made visible: X-ray cinematography. It had been possible to document the impact and the ignition — 150 milliseconds — using the sensors, but the first 10 to 20 milliseconds in which the airbag is ignited and starts to unfold had remained hidden; only single images of this phase existed — one picture for each airbag ignition.

“However, from one picture it is not possible to deduce the entire process,” explained Philip Helberg of the EMI Institute. With X-ray cinematography, which is based on flash X-ray technology, it is possible to create series of images at short intervals of at least 10 microseconds or 100,000 images per second (in theory). However, due to the X-ray sources, the researchers restrict themselves to eight images.

These images are enough to analyze the ignition of an airbag. With the help of these pictures manufacturers can find out how they should be stored in order to unfold in an optimum manner.