Adaptable Robotic Gripper Inspired by Sea Anemones

Innovation: Academia

Southwest University of Science and Technology

2020

Image: Yangfan Xiao / Unsplash / CC BY SA - Creative Commons Attribution + ShareAlike

Capture, Absorb, or Filter Solids

Some living systems must secure solid particles such as sediment, usually to keep the particles from hindering their health or activity. The most common way in which they do this is through filtering. To be effective, a filtering system must be appropriate to the sizes of solid particles to be captured and must capture only what is needed. It must also be effective in the appropriate media–air, water, or sometimes solids like soil. An example is mangroves, which are trees that grow along ocean coasts. Their root system slows down and settles sediment out of the water, building up soil to support the mangrove ecosystem.

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Modify Size/Shape/Mass/Volume

Many living systems alter their physical properties, such as size, shape, mass, or volume. These modifications occur in response to the living system’s needs and/or changing environmental conditions. For example, they may do this to move more efficiently, escape predators, recover from damage, or for many other reasons. These modifications require appropriate response rates and levels. Modifying any of these properties requires materials to enable such changes, cues to make the changes, and mechanisms to control them. An example is the porcupine fish, which protects itself from predators by taking sips of water or air to inflate its body and to erect spines embedded in its skin.

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Robotic gripper from Southwest University of Science and Technology

Benefits

Versatile
Adaptable

Applications

Medical devices
Underwater exploration

UN Sustainable Development Goals Addressed

Goal 9: Industry Innovation & Infrastructure

The Challenge

Robotic grippers are often designed with multiple finger-like components that help grasp objects. Although these have proven to be effective, the multiple components and joints can be difficult to control and are vulnerable to breaking. If the robots break, or are unable to grip a variety of objects, they will need to be re-made, leading to increased costs.

Innovation Details

The doughnut-shaped robotic gripper was inspired by the way sea anemones capture prey. Liquid pressure inside the ring controls how the robot grips and releases objects by adjusting a thermoplastic skin. When the inner skin of the ring is pulled, the exterior skin rolls inward to form a suction. By adjusting the length of the skin and the direction it rolls, researchers can control whether the robot picks up, fully engulfs, or releases an object.

Biological Model

Sea anemones are able to drastically change shape due to two mechanisms. The first is their central cavity, which has ciliary pumps that can re-inflate parts of the body by pumping water. The second mechanism is a supportive, viscoelastic, gel-like substance (mesoglea) that makes up their walls.

See Related Strategy

a large group of bright orange sea anemones with many small white tentacles

Biological Strategy

Body Changes Shape

Sea anemones

The central cavity of sea anemones is reinflated by water pumping in at low pressures thanks to ciliary pumps.

References

Journal article

Bionic torus as a self-adaptive soft grasper in robots

Applied Physics Letters

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