Shape-shifting elastic bubbles and shells as unit cells for morphing materials

We will develop shape-morphing materials with a hierarchical architecture of liquid crystal polymer shells that contain either a bubble of gas or a droplet of liquid, and that respond to light with complex shape transformation. The polymer shells will incorporate molecular motors or switches covalently in their design, as means to convert light into molecular movement and hence into deformation of the shells. Shape transformations of individual shells will be transmitted at a higher hierarchical level by promoting cohesion between the shells, while keeping an eye on their functional integrity. The cohesive networks that will be formed will display tissue-like shape-transformation in response to illumination. The specific goals of the research program are: i) To build a library of shape-shifting shells of liquid crystal polymers that respond to light with pre-programmed, anisotropic and reversible shape changes, because they incorporate molecular motors and switches in their design. These objects will be produced in microfluidic systems to optimize control over molecular orientation and to ensure low size dispersion. ii) To assemble the bubbles and shells into macroscopic architectures, in which inter-shell adhesion will be of primary importance to allow for amplification of a cohesive motion, from the shape-shifting units up to the whole material. We will use either entropic adhesion or multivalent interactions to promote adhesion between liquid crystal polymer networks. The research builds on the track record of Katsonis in designing molecular materials operated by the collective action of molecular motors and switches, including in droplets of liquid crystals – both considered as isolated units (Nature Commun. 2016) and after incorporation into networks (Sci. Rep. 2015). The proposal is further supported by active collaborations covering synthetic organic chemistry, multivalent interactions and non-conventional microfluidic systems. The shape-morphing materials developed in the course of this research will both embody and promote new engineering principles for adaptive matter. Ultimately, these tissue-like materials will also provide new insights into the interplay between cell shapes, cell deformation and emergent properties in tissues.