The active component of the thermal resonator is a foam made up of copper or nickel that is infused with a phase-changing wax known as octadecane, which liquifies and solidifies at certain temperatures. The foamy mix is coated in a layer of graphene, which is an excellent thermal conductor.
Researchers 3D-print WiFi-connected Objects That Don’t Need Power – The Objects Contain Antennas That Reflect Surrounding WiFi Signals.
“But the big challenge is how do you communicate wirelessly with WiFi using only plastic? That’s something that no one has been able to do before.” To do this, the team used things like 3D-printed springs, gears and switches that could be used to translate motion into antenna-transmitted information.