2019 AIChE Annual Meeting

(289e) Programming Deformation in Liquid Crystalline Elastomers

Authors

Timothy White - Presenter, University of Colorado
Hayden Fowler, University of Colorado
Anesia Auguste, Air Force Research Laboratory
Liquid crystal elastomers (LCEs) have exceptional promise as actuating materials. This presentation will detail the less known but equally compelling nonlinear deformation of these materials to mechanical load. Specifically, we will detail a methodology to realize surface-induced alignment of homeotropic orientation in LCEs. LCEs in the homeotropic orientation maintain exceptional nonlinearity in mechanical deformation, agnostic of loading directions. Inkjet printing of the alignment materials localizes regions of homeotropic and planar orientation within a single monolithic LCE element. By directing the self-assembly and orientation of the LCE, a material of continuous composition can be prepared in which the localized properties can be rationally designed. Near-zero Poisson’s ratio is observed in an LCE patterned in the square lattice configuration. Additionally, the preparation of rugged, flexible electronic devices is demonstrated via designed local control of mechanical deformation. This additively manufactured device withstands catastrophic mechanical deformations which would be normally expected to destroy such a device. Local programming of the deformation, enabled by manipulating the genesis of the polydomain orientation in these materials, will be discussed as a means of realizing true omnidirectional nonlinear deformation..