Lampreys are able to stay securely attached to whales and sharks as they hurtle through the ocean, so you’d think they could teach us a thing or two about suction. It turns out that they can indeed, as scientists have developed a lamprey-inspired suction cup that can lift 850 times its own weight.
Lampreys achieve suction via an “oral disc” consisting of a soft lip around the outside, and a ring of teeth on the inside. The teeth dig into the nooks and crannies of the host animal’s skin, while the lip forms an airtight, watertight seal.
Peking University’s Prof. Junzhi Yu and colleagues have replicated that mechanism in a device inspired by the oral disc of the Far Eastern brook lamprey, a freshwater species found in China, Japan, Russia and other regions.
Cyborg and Bionic Systems
The disc-shaped gadget features a soft silicone outer lip, at the center of which is a round core composed of a temperature-controlled Shape Memory Polymer (SMP).
When the device is pressed onto a surface, the silicone lip immediately forms a seal, just like a regular suction cup. A heater directly behind the core then warms it to a temperature of 33 ºC (91 ºF), causing the SMP to become soft and rubbery. This allows it to get sucked right into all the microscopic crevices and pores of the surface, by the vacuum created by the seal.
When the heater is subsequently switched off, the SMP hardens into that same “locked in” configuration. It stays that way until it’s heated again, and will maintain a secure grip even if the silicone lip’s seal is broken.
In lab tests, the 70-gram (2.5-oz) suction cup was able to generate enough pull-off force to lift objects weighing over 850 times its own weight, both in the air and underwater. And unlike a traditional suction cup, it had no problem adhering to rough, porous, or irregularly shaped objects – it lifted everything from a desk to a wrench to a brick to a conch shell.
“The application scenarios for this technology are vast,” say the scientists. “We envision this technology being deeply integrated into various robotic platforms, playing a crucial role in deep-sea resource exploration, marine engineering maintenance, and amphibious emergency rescue operations.”
A paper on the research was recently published in the journal Cyborg and Bionic Systems.
Source: EurekAlert
