Shape Memory Alloy (SMA) actuators are great in soft robotics for many reasons, but a major drawback is that their response rate is largely limited by the cooling rate.  For many applications, it makes sense to cool (and heat) SMA’s with water.  However, when a wet SMA actuates, it constricts, and the tube it is in needs to constrict with it.

This video shows how to make a corrugated tube very quickly from a drinking straw.