Got a dirty office window? Normally you’d have to wait for the cleaner to come, but a tech company Pufeng Intelligent Technology Co., Ltd based in Xiamen City, east China's Fujian Province seems to have found the solution – a window-cleaning robot. Equipped with 150+ sensors and six various propellers, it attaches itself to the building's surface with 18-kg vacuum grippers. It is said to be 10 times more efficient than manual window washers, with a cleaning speed of 120 square meters per hour. The robot is expected to enter the marketing phase within the next six months.