Shape-matching soft mechanical metamaterials

Area of Science:

• Materials Science and Engineering
• Mechanical Engineering
• Additive Manufacturing

Background:

• Architectured materials offer unique mechanical properties through rational geometric design.
• Metamaterials with auxetic and conventional unit cells can exhibit unusual deformation behaviors.
• Controlling the final shape of deforming materials is crucial for advanced applications.

Purpose of the Study:

• To introduce and demonstrate "shape-matching" metamaterials capable of achieving pre-defined shapes upon deformation.
• To establish a computational framework for mapping desired planar shapes to specific geometric designs of cellular structures.
• To explore the potential applications of these shape-matching metamaterials in fields like soft robotics and medical devices.

Main Methods:

• Utilized computational models to perform forward-mapping from planar shapes to geometrical designs of cellular structures.
• Validated computational models by comparing predictions with experimental results from indirectly additively manufactured specimens.
• Employed Fourier series to describe arbitrary shapes and devised cellular structures to approximate these target contours.

Main Results:

• Successfully demonstrated the capability of shape-matching metamaterials to deform into complex, arbitrary shapes.
• Validated the accuracy of computational models through experimental verification.
• Showcased shape-matching capabilities by conforming to the contours of a scapula model, a pumpkin, and a Delft Blue pottery piece.

Conclusions:

• Shape-matching metamaterials, designed with specific geometries of auxetic and conventional unit cells, can achieve target shapes upon deformation.
• The developed computational forward-mapping approach is effective for designing such shape-adaptive materials.
• These novel metamaterials hold significant promise for applications requiring precise shape conformity, such as in soft robotics and wearable medical devices.