Patterning order and disorder with an angle: Modeling dual-phase nematic elastomer ribbons

A wide variety of out-of-plane actuation behavior can be encoded in liquid crystalline polymer networks thru implementing complex microstructures in the nematic director field. While most imprinted designs are based on spatial variations of the nematic director, no theoretical studies have been made on dual-phase elastomers: samples that combine well-defined regions with nematic order and isotropic regions. Depending on patterning design, these materials exhibit a variety of actuation behavior, going from helical twisting to chiral bending and accordion folding. By implementing finite element elastodynamics simulations at the continuum level, we demonstrate this actuation variety based on several key design factors: director orientation, pattern orientation, as well as domain and sample size. Our simulations studies show an exceptional agreement with experimental observations, providing insights for further development of soft solids with complex hybrid microstructures.