Rubber bands do the exact opposite ... Rubber is never going to displace standard refrigerants, but this is a great demo of the principles of entropic force. For more thermodynamic fun, check ...

After waking up with a puffy face, it was the perfect time for these rubber bands to work their magic. Unable to find any standard brown rubber bands lying around, I improvised with two hair ties.

Flexible filament like TPU is one option, but [NagyBig] designed a simple bracelet to ask: how about embedding rubber bands or o-rings into the print itself? Embedding objects into prints usually ...