And finally, when the bump sensors have detected the bottom of the window, the device will stop, and wait to be picked up.

Repeating this process, the automatic window cleaner works its way down the window, in what we call in a ‘Z’ pattern.

Then the device will set off in the other sideways direction, in a straight line, to the opposite window frame.

And when the bump sensors detect the window frame, the robotic window cleaner will ‘crab’ its way down the window frame a little bit.

Then, rotating the pads alternately to move sideways, the device will eventually bump against the window frame on either side.

And once the bump sensors detect the window frame, the robotic window cleaner will change direction, and start moving horizontally.

The device will climb to the top of the window, alternately rotating the pads, until it bumps against the top of the window frame.

The design is about 30cm long and 15 cm wide, and there are two pads about 15cm in diameter which adsorb onto the glass.The first type of robot window cleaner Australia saw was one that uses rotating circular microfiber pads.

Robotic window cleaner