posted on 2023-12-12, 07:30authored byLuke McDougall, Jeremy Herman, Emily Huntley, Samuel Leguizamon, Adam Cook, Timothy White, Bryan Kaehr, Devin J. Roach
Liquid crystal elastomers
(LCEs) are a class of active materials
that can generate rapid, reversible mechanical actuation in response
to external stimuli. Fabrication methods for LCEs have remained a
topic of intense research interest in recent years. One promising
approach, termed 4D printing, combines the advantages of 3D printing
with responsive materials, such as LCEs, to generate smart structures
that not only possess user-defined static shapes but also can change
their shape over time. To date, 4D-printed LCE structures have been
limited to flat objects, restricting shape complexity and associated
actuation for smart structure applications. In this work, we report
the development of embedded 4D printing to extrude hydrophobic LCE
ink into an aqueous, thixotropic gel matrix to produce free-standing,
free-form 3D architectures without sacrificing the mechanical actuation
properties. The ability to 4D print complex, free-standing 3D LCE
architectures opens new avenues for the design and development of
functional and responsive systems, such as reconfigurable metamaterials,
soft robotics, or biomedical devices.