If the friendly neighbourhood superhero Spider-Man is a source of inspiration for you, at least as far as climbing up walls is concerned, then you may be in luck. Researchers at the Zhejiang University in China may be able to fulfil the dreams of thousands of Peter Parker fans. They have created a device that allows humans or robots to scale walls like Spider-Man. While suction cups usually require an unbroken surface for someone to climb up a wall, the gadget, created by Xin li and Kaige Shi is able to grip rough, uneven surfaces as well.
Standard vacuums rely on the unbroken seal between the atmosphere and the gadget's inner vacuum to function through suction and accordingly, researchers have said that the most difficult problem they faced was vacuum leakage, which results in suction failure. They employed the 'ZPD method' to overcome the vacuum leakage that prevents the devices from working on rough surfaces. According to the study's authors, "The ZPD suction unit forms a rotating water layer on the periphery of the vacuum zone, and the resulting inertial force generates a steep pressure gradient”. They add that this results in the maintenance of a high vacuum at the centre of the vacuum zone, even though the pressure at the boundaries of the device remains the same as the atmospheric pressure. This basically means that the device squirts water towards the edges of the device's suction cups to maintain an even seal in the middle, the report added.
The researchers are trying make the device a fully self-contained unit capable of operating on its own by cutting down water consumption and making the unit function for a longer time with lesser water. If the water-powered wall-climbing device becomes a practical reality, it could be really handy in a variety of use cases, including rescue missions, for fire tenders and even for the maintenance and cleaning of skyscrapers.