Programmable Shape-Shifting Soft Robotic Structure Using Liquid Metal Electromagnetic Actuators.

Area of Science:

• Robotics
• Materials Science
• Mechanical Engineering

Background:

• Advancements in soft robotics, stretchable electronics, and flexible medical devices require novel materials capable of shape change.
• Existing flexible structures often lack independent control or shape retention after actuation.

Purpose of the Study:

• To present a new soft robotic structure capable of programmable 3D shape morphing.
• To demonstrate electromagnetic actuation using embedded liquid-metal conductors for shape control.
• To investigate the role of granular jamming for shape memory.

Main Methods:

• Fabrication of volumetric pixels (voxels) with granular cores and liquid-metal embedded silicone shells.
• Application of electrical current for electromagnetic actuation via Lorentz force.
• Utilizing vacuum pressure for independent voxel control.
• Multiphysics simulation and experimental characterization including 3D digital image correlation and 3D magnetic field scanning.

Main Results:

• The proposed structure successfully morphs into various 3D configurations with amplitudes exceeding 10 mm.
• The granular core enables shape retention after actuation due to the granular jamming effect.
• The shape-changing process is demonstrated to be fully reversible and repeatable.

Conclusions:

• The developed soft robotic structure offers a promising platform for advanced flexible devices.
• Independent control of voxels allows for complex and programmable shape transformations.
• The combination of electromagnetic actuation and granular jamming provides robust and repeatable shape morphing capabilities.