[RyanCahoon]

Originally Posted by jspatz1

Every material on the robot took energy to create, that does not mean they are contributing energy to the function of the robot. Wouldn't the sublimation of the dry ice be a net negative (consumer) process in terms of energy? How could it contribute stored energy to the robot?

Hmm would that classified as stored energy by deformation of a robot part (where in this case the deformation would be freezing)? IMO you also have a valid point about it not being stored energy; it seems like it would be "stored entropy."

As to how you could use dry ice to provide power to a robot... YouTube: Stirling Engine Running On Dry Ice. Maybe you could use the Stirling engine to power a fan to cool your motors? The energy for this would, as you point out, not be coming from the dry ice but from the ambient temperature, and under those terms could be ruled illegal.