Cuboidal Deformation of Multimaterial Composites Prepared by 3-D Printing of Liquid Crystalline Elastomers

Multimaterial 3-D printing (3DP) of isotropic (IsoE) and liquid crystalline elastomers (LCE) yields spatially programmed elements that undergo a cuboidal shape transformation upon heating. The thermomechanical deformation of 3DP elements is determined by the geometry and extent of the isotropic and anisotropic regions. The synthesis and experimental characterization of the 3DP elements are complemented by finite element analysis (FEA). Calculations emphasize that the cuboidal deformation of the myriad 3DP elements is a manifestation of local stress gradients imparted by local control of the material composition and anisotropy. Varying the rectilinear spatial distribution of the multimaterial elastomer composites produces complex, multistable states that provide insights into how stress gradients drive multimaterial elastomer actuation. The thermomechanical stimuli response of the multimaterial elements is explored as a tactile element.