Don't ask me how these might work, but it's fun to think about at least. From Mashable:
If you've ever wished your house would automatically clean itself, so you could get a little free time — you're not alone. An industrial-design student in Colombia has conceptualized an automated cleaning system in which flying robots would do all the dirty work.
Designer Adrian Perez Zapata came up with "Mab," which harnesses hundreds of mini-robots equipped with a cleaning solution to tidy up homes. Zapata, 23, is among 20 semifinalists in the 2013 Electrolux Design Lab competition. This year's theme is "inspired urban living," so undergraduate- and graduate-student participants can submit design solutions in the categories of social cooking, natural air and effortless cleaning.
The Mab concept requires users to load water and a chemical substance into the system's spherical core. The cleaning liquid is then distributed to 908 mini-robots, which are each equipped with propellers for flying. After that, the mini-robots are dispatched, scanning the home and cleaning surfaces with droplets of fluid. Dirt is captured and carried back to the core. The little bots would be powered by the solar energy collected via their wings.
Electrolux Design's Thomas Johansson called Mab a "bold solution, which mimics the collection of honey bees."