Tailored helix morphing of 3D-printed liquid crystal elastomer bilayers

<h2>Summary</h2> Helical morphologies are ubiquitous and exhibit versatile bio-functionality in natural plants. While replicating these helical shapes in artificial systems is promising, the resulting helices are far less complex than those found in nature, limiting their applications. In this study, we propose a strategy for tailoring helical morphologies using thermally responsive liquid crystal elastomer bilayers. The bilayers are fabricated using 3D printing, enabling the precise programming of helical features. Through numerical simulations and experiments, we investigate how printing patterns influence the resulting helical shapes and further elucidate the energy-based mechanism governing shape selection. Phase diagrams are developed to guide the design of the desired, complex helical shapes. We showcase the multifunctional applications in biomimetic morphing of intricate helical morphologies in leaves, soft grippers conforming to irregular objects' shapes, and rolling robots with tunable self-turning capability. This work opens an avenue for a biomimetic helix with multifunctionality.