Heating milk in the microwave is a convenient way to make espresso coffee, but it never gets hot enough due to localised hotspots boiling over before the bulk of the fluid is heated through. This device continually stirs the milk or coffee during heating to ensure the fluid is uniformly heated throughout. Now you can enjoy scolding hot microwave coffee without the mess.
Just add bamboo skewers cut to fit and your choice of food grade plastic or wooden stirrer(s). A variety of configurations are possible. Legs can be long enough for the device to stand up on its own to make it easier to catch drips or just long enough to keep it on the mug. The turning arms can be single or double sided for balance or compactness respectively.
Perhaps a light coating of wax would serve as a food safe lubricant for the gears, which can sometimes twist and jam on rough edges of the print.