Programming complex shapes in thin nematic elastomer and glass sheets

Area of Science:

• Materials Science
• Soft Matter Physics
• Mechanics of Materials

Background:

• Nematic elastomers and glasses are solids exhibiting spontaneous distortion in response to stimuli.
• Recent synthesis of heterogeneous sheets allows for complex shape actuation with high energy density.
• These materials show significant promise as soft actuators.

Purpose of the Study:

• To introduce a key metric constraint governing shape-changing actuation in nematic elastomer and glass sheets.
• To explore the diverse range of shapes achievable under this constraint.
• To provide insights into the fundamental principles driving shape transformation.

Main Methods:

• Introduction of a novel metric constraint for shape-changing actuation.
• Demonstration through two classes of examples: nonisometric origami and lifted surfaces.
• Analysis of energy minimization principles involving stretching, bending, and material heterogeneity.

Main Results:

• Identification of a critical metric constraint that dictates shape-changing capabilities.
• Showcasing of complex, non-trivial shapes through nonisometric origami and lifted surfaces.
• Understanding the interplay of mechanical forces and material properties in actuation.

Conclusions:

• The metric constraint provides a powerful tool for designing and controlling soft actuators.
• Nematic elastomer and glass sheets offer a versatile platform for programmable shape morphing.
• Energy minimization principles are crucial for deriving and understanding actuation behavior.