Biodegradable and Flexible Wood-Gelatin Composites for Soft Actuating Systems

Area of Science:

• Materials Science
• Robotics Engineering
• Biomaterials

Background:

• Soft robotics relies heavily on compliant materials, often petroleum-based and non-recyclable, raising sustainability concerns.
• Existing bio-derived alternatives like gelatin lack the necessary mechanical performance for soft actuators.
• There is a growing need for sustainable, high-performance soft materials in robotics.

Purpose of the Study:

• To develop a flexible, entirely biobased composite material for soft robotics applications.
• To address the limitations of current soft materials regarding sustainability and mechanical properties.
• To demonstrate the potential of the novel composite in creating advanced soft actuators.

Main Methods:

• Reinforced a gelatin-glycerol matrix with structure-retained delignified wood to create the DW-flex composite.
• Characterized the anisotropic mechanical behavior of the DW-flex composite.
• Designed and modeled a fin ray-inspired gripper finger utilizing the DW-flex composite.
• Developed a proof-of-concept demonstrator for gripping a soft object.

Main Results:

• The DW-flex composite exhibits highly anisotropic mechanical behavior: high strength and stiffness along the fiber direction, and high deformability perpendicular to it.
• The anisotropic properties enable tailorable twist-bending-coupled motion in robotic actuators.
• A functional gripper finger and a soft object gripper demonstrator were successfully built and tested.
• The composite was confirmed to be entirely biodegradable in soil.

Conclusions:

• The developed DW-flex composite offers a sustainable, high-performance alternative to petroleum-based soft materials for robotics.
• Its tunable anisotropic properties open new avenues for designing complex soft actuators.
• The biodegradability of DW-flex supports environmentally conscious approaches in soft robotics.