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What it is &  How it works

  
Automobile airbags are inflated with a special pressurized cylinder. They must work reliably for many years, so the cylinders can't have even "micro" leaks. Our project sponsor, TRW Automotive, tests for leaks with large, slow and expensive equipment. They asked the ASU Poly Capstone students to design a system using the newest solid state sensors, one that's economical, fast, and as sensitive as the equipment they have now. 
 
In response, our students developed the  Hydrogen Leak Detection System shown here. With it, a worker can rapidly test each airbag deployment cylinder for even the smallest leaks. Here's how it works:
1. A quality technician inserts the airbag cylinder between the two sensor heads, closes a safety cover (not shown), and pushes the start button.

2. A pneumatic actuator closes & seals the sensor heads around each end of the cylinder.

airbag prototype
 3. Solid state hydrogen sensors in each sensor head will detect any leakage, even at parts-per-million levels, and log the results on a computer.

4. After the test, the sensor heads open up, and an indicator light tells the technician whether the cylinder passed the test or not.
Our team designed the system, built it, and demonstrated that it works. The prototype was delivered to our sponsor on May 1, 2002, along with a full set of engineering drawings, manufacturing and calibration data, and a user's manual. We delivered it  using only 3/4 of our $10K budget. Thank you, TRW! We had a great time with this!