They’re stupid expensive, but they are damn cool. Years ago, I worked on a project that could have used them, but we ended up strain-gauging a different component in the assembly. It was the right decision, but it still made me sad. If I’m ever super rich, I’m going to randomly scatter these throughout my car and just collect data for no good reason. I will also host C4 Corvette demolition derbies. You’re all invited.

http://www.strainsert.com/product-categories/force-sensing-bolts-studs/