The clean machine

The SIRIUSc: It recycles the cleaning water

Like a fly climbing a wall, this robotic window cleaner scampers up the side of skyscrapers ensuring they retain their gleam.

The machine hangs on to a vertical surface using vacuum suckers. Its locomotive design allows it to traverse obstacles such as lintels, ventilation grids and sun-blinds.

It even recycles the water it uses to clean the windows - no rushing to a tap, no mess.

The robot's developers at the Fraunhofer Institute for Factory Operation and Automation IFF, in Magdeburg, Germany, say it will keep working in winds that would be regarded as dangerous for human cleaners.

Dr Norbert Elkmann of the IFF explains: "Our objective was to develop a complete system which, in addition to the robot and the cleaning system, was able to provide its own safety and security system and carry its own supply of materials."

SIRIUSc, as the robot is known, can work on many different kinds of façade. It carries all its brushes and water. And because all the water is filtered and returned to the cleaning cycle, the windows are instantly dry and no water runs or drips down the side of the building.

Dr Elkmann says SIRIUSc will clean up to 120 square metres per hour.

The German robot was recently showcased at the international "Cleaning in the new Millennium" exhibition and fair in Singapore.