The device, which resembles a Roomba vacuum cleaner, attaches itself to a pane, maps out its perimeter and proceeds to clean the surface, playing a tinny tune when the work is completed.

WSJ: Window-Washing Robots Rise; Humans Balk

During the past 20 years the industry has striven to clean up its act, at least on the surface.

FORBES: On-Line Brokers and the (Unfulfilled) Promise of Tokyo's "Big Bang"

Drop the AutoMee S onto an iPad and it will buff the finger prints away, wandering around the screen in straight lines, ricocheting of the edges until the entire surface is clean.

CNN: A tiny Roomba for your phone and tablet

"The pencil skirt has the perfect shape to highlight a print because it's a really clean surface, " said designer Joseph Altuzarra of the high-waisted, nipped-in style to which he returns season after season.

WSJ: Rethink: Pencil Skirts | Off Duty Spring 50

The Opificio's restorers plan to clean David by applying compresses of distilled water to the marble surface to draw away dirt.

NPR: Restoring Michelangelo's David

Rainfall helps keep it clean: water seeps through the rubber and drains into pipes just below the surface.

ECONOMIST: Monitor