Researchers have designed new suction devices that can be used on rough surfaces. What’s more, these devices could also lead to the development of ‘Spider-Man-style’ climbing robots and robotic arms with grasping capabilities. Researchers from the American Institute of Physics (AIP), conventional suction are not effective when it comes to maintaining a pulling force on rough surfaces. That is, however, due to vacuum leakage which leads to suction failure.
As described in the journal Physics of Fluids, researchers developed a zero-pressure difference (ZPD) method in these new devices which in turn helped them overcome the vacuum leakage limitations. As the scientists explain, the new technique makes use of a high-speed rotating water ring between the surface and the device's suction cup. This leads to the creation of a centrifugal force for gripping rough surfaces, helping maintain the vacuum.
"There are many applications of our design, but we think the wall-climbing robot will be the most useful," said Xin Li, study co-author from AIP.
"Compared to other wall-climbing robots, the robot with our ZPD-based suction unit achieves surprising improvement in performance," Li said.
The study noted that the centrifugal force of the rotating water cancels out the pressure difference at the boundary of the vacuum zone and the surface, which further prevents vacuum leakage. This technique essentially enables the device to maintain a high vacuum pressure inside the suction cup. Scientists describe ZPD suction unit as energy-efficient, and smaller and lighter than typically used suction devices.
"Experiments showed that a 0.8 kilogrammes ZPD suction unit generated a suction force of over 245 Newtons on rough surfaces with a power consumption of less than 400 Watts," the researchers wrote in the study.
Unlike this technique, a traditional suction unit of the same size needs a vacuum pump that requires several kilowatts of power while weighing dozens of kilogrammes to generate a similar suction force. The scientists also tested the ZPD unit with three different suction sizes and applications: one on a robotic arm to grip and handle objects, in addition to a hexapod wall-climbing robot, as well as a Spider-Man-like wall-climbing device.
"The next step in this research is to cut down the water consumption. If the water consumption can be reduced, the suction unit will work for a very long time with little water so that the wall-climbing robot could carry its own water instead of being connected to a supply," Li added.
(Photo: Franck V. / Unsplash)