Space tech helps create safer automobiles

A thin foil sensor developed to detect the pressure on a spacecraft's wings during re-entry is now helping build safer cars, European researchers say. German automaker Volkswagen is using the flexible "space foil" as a super-thin and accurate sensor to measure every deformation sustained by cars during crash tests, a release from the Paris headquarters of the European Space Agency reported. In the early 1990s, European engineers turned to "piezoelectric" foil, intended for spacecraft use, because regular instruments were too bulky and added too much drag. Piezoelectric materials can convert physical effects such as vibration and pressure into minute electric pulses, making them ideal as extremely lightweight sensors able to cover an entire surface without distorting the results by adding drag. VW was attracted to the material because the space sensors would solve a problem encountered in crash tests: sensors on cars are often destroyed upon impact, making it difficult to collect highly accurate data throughout the crash process. The thin, flexible piezoelectric sensors are simply applied to the car's surfaces and move with the metal as the car crashes rather than being destroyed by the impact. "We wanted to know at which moment which parts of the car are deformed," VW engineer Jens Weinrich said. At the end of each strip, a thin, flexible printed circuit board records the electrical impulses created by the mechanical deformations. We wanted not just qualitative, but also quantitative results," Weinrich said. "We wanted to know where it folded, and how much it folded."