Soft Robots with Plant-Inspired Gravitropism Based on Fluidic Liquid Metal

Area of Science:

• Robotics
• Materials Science
• Biomimetics

Background:

• Plants exhibit gravitropism, adjusting growth direction to optimize energy capture, a trait not yet replicated in electronic-free soft robots.
• Developing self-regulating soft systems that respond to environmental stimuli like gravity is a significant challenge in robotics.

Purpose of the Study:

• To create soft actuators capable of responding to gravitational fields without relying on electronics.
• To explore the potential of liquid metal's unique properties for developing gravitropic soft robots.

Main Methods:

• Fabrication of soft actuators using magnetic printing of liquid metal circuits on thermoresponsive liquid crystal elastomers.
• Utilizing the gravity-regulated resistance and Joule heating of liquid metal to induce self-regulated bending and motion.
• Integrating actuators with a monostable tape spring for controlled oscillation and bionic walker locomotion.

Main Results:

• Demonstrated acceleration-regulated soft actuators that autonomously adjust bending in response to gravity.
• Developed a gravity-interactive soft gripper with controllable grasping and releasing capabilities.
• Achieved electronics-free control of a bionic walker through self-regulated oscillation.

Conclusions:

• This work introduces a novel approach for creating electronics-free soft robots and reconfigurable devices inspired by plant gravitropism.
• Liquid metal's properties are leveraged to enable soft robots to perceive and react to gravity and acceleration.
• The developed technology opens new avenues for bio-inspired, self-regulating robotic systems.