Decoupling how structure and processing affects the properties of Liquid Crystal Elastomers.*

The apparently simple and facile addition of liquid crystalline order to a crosslinked polymer network elevates a material from a conventional entropic elastomer to a mechanically complex and stimuli responsive system. The mechanical properties evolved - anisotropy, mechanical dissipation, and negative Poisson ratios - are intrinsic properties which are reminiscent of those found in natural materials, and which typically are only seen in composite materials featuring a micro- or macro-scopic structure. The emergent shape actuation behaviours are responsive to a wide range of thermal, optical, chemical, and electrical stimuli and again the behaviour of example devices mimics those seen in living organisms.

Despite all these celebrated phenomena and example devices, much remains to be understood in terms of how molecular structure, monomer compositions, and processing influences the properties and behaviours of LCEs, particularly when understanding their dynamical behaviours.

In this talk, I will focus on our work to decouple the effects of structure, composition, and processing on the properties of liquid crystal elastomers. I will consider three examples: The compositional effects on the dynamic and quasi-static mechanical behaviours of LCEs, tuning and understanding the processing parameters of 3D printed liquid crystal elastomers, and the properties of chemically identical liquid crystal elastomers templated with different liquid crystalline phases.