Fun with Chemistry
Open Source Home build: Remote temperature sensing magnetic stir bar
The author of the AppliedScience YouTube channel describes how he developed a remote temperature sensing magnetic stir bar. This is really quite useful for closed flasks and the like. He open sourced the project and you can find the build information (links below).
Meanwhile, the company GateScientific sells remote pH and temperature sensing magnetic stir bars, using the same RFID technology.