We have talked in the past about the wild slingshots that Joerg Sprave builds. His latest slingshot uses a heating element to keep the rubber band at its ideal power. When you draw the rubber band back on a normal slingshot and then don’t shoot it, right away, the band cools and the slingshot loses power.
Sprave designed a slingshot with an enclosed box that has a heating element inside. That heating element is powered by a rechargeable battery. With this system, you can draw the rubber band back and then lock it to fire later without losing power.
The heating elements are controlled by a switch on the slingshot and will warm the rubber band up to its original power. This is pretty cool and you can see the slingshot and why it works in the video below.