In context
In 2023, bio-inspired soft robotics was a rapidly advancing field, with researchers increasingly turning to plant movements for novel actuation strategies. The Venus flytrap, known for its rapid closure, offered a compelling model for developing fast, reversible, and structurally simple actuators, potentially useful in industrial gripping and flexible automation.
What was reported
A team from Northeast Forestry University investigated the Venus flytrap's movement mechanism at both micro and macro scales. Using plant sectioning and tissue clearing, they observed the leaf's vascular system and cell arrangement, finding elongated cells perpendicular to the midrib and oval cells parallel to it. High-speed imaging and VIC-3D strain measurement revealed that during closure, the maximum strain perpendicular to the midrib was about 2%, which was 2–4 times higher than parallel strain, indicating that bending deformation in that direction drives the rapid closure.
They developed a hydraulically driven bionic flexible leaf actuator, fabricated via 3D printing, and simulated its behavior using a porous media model and fluid-structure coupling. The simulation showed that under 2 MPa hydraulic pressure, the actuator achieved a maximum bending angle of 32.27° within 1 second. Experimental results from the prototype closely matched the simulation, confirming the feasibility of the approach and successfully reproducing the fast bending motion of the Venus flytrap leaf.
The study also modeled the closure dynamics, fitting parameters such as a silent time of 0.12 s and characteristic times of 10 s, with peak horizontal velocity reaching −0.14 m/s and angular velocity up to −6.9 rad/s.
Why it mattered
This work demonstrated a practical method for designing bio-inspired soft actuators that are fast, reversible, and easy to control, leveraging water-based actuation rather than traditional motors. Such actuators could lead to simpler, more flexible gripping systems in manufacturing, where gentle yet rapid handling of delicate objects is required, and may inspire further plant-based robotic solutions.
"The proposed biomimetic flexible leaf actuator, employing fluid-structure coupling simulation, is capable of achieving bending deformation within 1 second under a hydraulic pressure of 2 MPa."
Source: 《机器人》期刊 (robot.sia.cn) · Published 2023-11-10 · “捕蝇草运动机理及其仿生驱动器的仿真和实验研究”