Polyelectrolyte microcapsules can be produced either by the layer-by-layer assembly technique or the formation of polyelectrolyte complexes at the liquid-liquid interface. Here, we describe the design and construction of DNA microcapsules using the cooperative assembly of DNA and amine-functionalized polyhedral oligomeric silsesquioxane (POSS-NH2) at the oil-water interface. "Janus-like" DNA surfactants (DNASs) assemble in situ at the interface, forming an elastic film. By controlling the jamming and unjamming behavior of DNASs, the interfacial assemblies can assume three different physical states: solid-like, elastomer-like, and liquid-like, similar to that seen with thermoplastics upon heating, that change from a glassy to a rubbery state, and then to a viscous liquid. By the interfacial jamming of DNASs, the liquid structures can be locked-in and reconfigured, showing promising potentials for drug delivery, biphasic reactors, and programmable liquid constructs.