Rotational 3D printing of active-passive filaments and lattices with programmable shape morphing

Area of Science:

• Materials Science
• Robotics
• Biomimetics

Background:

• Natural filaments exhibit complex shape-morphing capabilities crucial for biological functions.
• Replicating this programmable shape-morphing in synthetic materials remains a significant challenge.
• Existing synthetic approaches struggle to precisely control intrinsic curvature and twist.

Purpose of the Study:

• To introduce a filament-centric strategy for programmable shape morphing in synthetic materials.
• To demonstrate direct encoding of natural curvature and twist fields within multimaterial filaments.
• To enable independent control over bending and torsion along the filament centerline.

Main Methods:

• Utilized rotational multimaterial 3D printing to fabricate elastomeric filaments.
• Controlled material distribution and helical liquid crystal mesogen alignment to prescribe curvature-twist fields.
• Incorporated active (liquid crystal elastomer) and passive regions within filaments for shape change upon heating.

Main Results:

• Successfully printed architected lattices with sinusoidal filaments exhibiting programmable contraction, expansion, and out-of-plane deformations.
• Demonstrated independent control of bending and torsion at every cross-section.
• Validated predictions using discrete elastic rod simulations of interconnected filaments.

Conclusions:

• Developed a novel method for creating shape-morphing matter with complex, programmable responses.
• Integrated active-passive elastomers, additive manufacturing, and computational modeling for advanced material design.
• Paved the way for applications in adaptive, robotic, and deployable architectures.