Soft Robotic Gripper Modelled on Pole Bean Tendrils Developed at University of Georgia
In December 2020, researchers at the University of Georgia developed a soft robotic gripper modelled on the twining behaviour of pole bean tendrils. The 3-inch device uses a single pneumatic actuator and an embedded fibre-optic sensor to grasp objects as small as 1 millimetre in diameter and characterise surface properties during contact.
Background
Soft robotic grippers had been a live research problem for years before this work. The basic appeal of soft robotics is that a compliant, flexible gripper can handle fragile or irregularly shaped objects that a rigid metal claw would crush or drop. But compliance brought its own difficulties.
Most soft grippers of this period were either good at grasping or good at sensing, not both at once. Detecting surface texture or object properties usually meant adding separate sensors, which added weight, complexity and points of failure. Getting a single low-power actuator to reliably grasp objects across a wide range of sizes was also hard. The geometry that works for a grape does not work for a matchstick. Researchers were still looking for mechanical designs that could bridge that gap without a great deal of extra hardware.
Plants turned out to be a useful place to look. Climbing plants solve a version of the same problem every time they grow: they find a surface, wrap around it and hold on, regardless of whether that surface is a thin wire or a thick branch. The pole bean tendril does this through a coiling motion driven by differential growth along its length. Several groups had begun drawing on plant mechanics for robotic inspiration, but translating the tendril’s behaviour into a working gripper with integrated sensing had not been done.
What happened
Researchers at the University of Georgia built a gripper that replicates the twining behaviour of pole bean tendrils. The device is about three inches long and uses a single pneumatic actuator, a component that moves by air pressure rather than by motors or cables, to produce a coiling motion. Because there is only one actuator, the control system stays simple. The gripper wraps around an object rather than pinching it, which lets it conform to whatever shape it encounters.
The sensing comes from a fibre-optic sensor embedded along the gripper’s elastic spine. Fibre-optic sensors work by detecting changes in the light passing through a flexible optical fibre when the fibre bends or is pressed. Here, the sensor tracked the twining angle as the gripper coiled, and used that information to characterise the surface the gripper had contacted, identifying properties such as texture. Grasping and sensing happened through the same structure, at the same time.
The gripper could hold objects as small as one millimetre in diameter. That was not the limit of what it could handle; the coiling mechanics also allowed it to grip larger objects without adjustment. The paper was published in Soft Robotics in December 2020. This was a laboratory demonstration, not a deployed system, but the design showed that a single compliant actuator combined with embedded optical sensing could manage a range of sizes and textures that would usually require more complicated arrangements.
Why it mattered
The gripper demonstrated that biologically inspired twining mechanics, combined with optical sensing, could enable a single low-complexity actuator to handle objects spanning a wide range of sizes and textures, a longstanding challenge in soft robotics. Integrating sensing and grasping in one compliant structure reduces the hardware overhead typically required for delicate manipulation. The work contributed to the broader programme of deriving robotic manipulation strategies from plant biomechanics.
Organisations
Sources
- A Tendril-Inspired Soft Gripper with a Fiber-Optic Sensor for Object Recognition.Soft Robotics (Mary Ann Liebert).Primary source
- Inspired by beans: Developing a robotic gripper that mimics plant tendrils.ScienceDaily.Secondary
- UGA engineers develop soft robotic gripper inspired by pole bean tendrils.University of Georgia College of Engineering.Official
Cite this page
AI Achievements. (2020). Soft Robotic Gripper Modelled on Pole Bean Tendrils Developed at University of Georgia. Retrieved 2026-08-22, from https://achievements.ai/milestone/soft-robotic-gripper-similar-pole-beans
@misc{achievements_soft_robotic_gripper_similar_pole_beans,
title = {Soft Robotic Gripper Modelled on Pole Bean Tendrils Developed at University of Georgia},
author = {{AI Achievements}},
year = {2020},
url = {https://achievements.ai/milestone/soft-robotic-gripper-similar-pole-beans}
}