STIR: Novel magnetically responsive and self-repairing particle-lipid-water gels: Exploring nanocapillarity as a tool for making materials with extraordinary properties

This exploratory project resulted in the discovery and testing of two responsive materials with extraordinary properties and wide areas of potential technological applications. The first one is a new smart gel system containing ultraflexible chains of magnetically responsive nanoparticles formed in multiphase water-oil systems. Liquid lipid shells condensed on the nanoparticles lead to directed assembly of microfilaments and networks via nanocapillary bridges. These liquid bridges allow for particle rolling and sliding, and the resulting chain flexibility was measured to be orders of magnitude higher than any other linear structures reported to date. The nanoparticlesÕ binding through soft, 'snappable' capillary forces provides facile means of creating self-repairing gels and new types of responsive multiphase composites. On the basis of the characterization of these capillary interactions, Velev et al. then introduced a new method for 3D printing with polydimethylsiloxane (PDMS). In their new method PDMS microbeads are bound through formation of capillary bridges to from an ink for three-dimensional printing. The 3D-printed PDMS structures exhibit high elasticities after crosslinking. These self-standing and highly flexible 3D printed PDMS structures can find applications in biomedical scaffolds and devices, novel electronics and soft robotics.