Biphasic liquids with shape-shifting and bistable microdomains

Liquids comprising two coexisting phases can form a range of stable and metastable states, including wetting films, droplets and threads1–3. Processes that permit rapid and reversible transformations between these morphologies, however, have been difficult to realize because physical properties required for rapid shape change (for example, low interfacial tension or viscosity) provide pathways for relaxation that result in short-lived states. Fully reversible formation of long-lived microdomain states would expand the palette of properties that can be accessed dynamically using biphasic liquids (for example, tunable optical metamaterials). Here we report the discovery of shape-shifting and bistable microdomains of a biphasic liquid system consisting of an isotropic oil and a liquid crystalline oil. The isotropic oil forms stable wetting films (‘original’ shape) between solid surfaces and an overlying liquid crystal phase, and, when exposed to a transient ( 24 h) spherical domains (‘temporary’ shape) stabilized by topological defects in the liquid crystal1,4,5. Subsequent application of an a.c. electric field of high frequency (1 kHz) triggers solitons to form in the liquid crystal6–8, creating kinetic pathways that lead to remarkably rapid (