Biomimetic Nonuniform, Dual-Stimuli Self-Morphing Enabled by Gradient Four-Dimensional Printing

Area of Science:

• Materials Science
• Biomimetics
• Additive Manufacturing

Background:

• Programmable nonuniform deformation is crucial for self-shape-morphing systems in biology and technology.
• Applications include drug delivery, biomedical devices, and robotics.

Purpose of the Study:

• To present a novel gradient four-dimensional (4D) printing method for biomimetic, nonuniform, dual-stimuli self-morphing.
• To enable precise control over shape transformation through material gradients.

Main Methods:

• Modeling and printing graded active materials with water-swelling properties in bilayer structures.
• Configuring smooth gradients of active material volume fraction.
• Utilizing a mathematical model and computational simulations to predict shape-shifting.
• Integrating graded water-responsive elastomers with heat-shrinkable shape memory polymers.

Main Results:

• Achieved programmable nonuniform shape transformation by regulating swelling ratio mismatch.
• Demonstrated dual-stimuli self-morphing structures responding to humidity and temperature.
• Validated predictions with mathematical models and simulations.

Conclusions:

• The gradient 4D printing method offers a versatile approach for designing complex self-morphing structures.
• This technique expands design possibilities for 4D printing and is compatible with various active materials.
• Paves the way for advanced applications in medicine, robotics, and beyond.