Fluids by design using chaotic surface waves to create a metafluid that is Newtonian, thermal, and entirely tunable.
In conventional fluids, viscosity depends on temperature according to a strict relationship. To change this relationship, one must change the molecular nature of the fluid. Here, we create a metafluid whose properties are derived not from the properties of molecules but rather from chaotic waves excited on the surface of vertically agitated water. By making direct rheological measurements of the flow properties of our metafluid, we show that it has independently tunable viscosity and temperature, a quality that no conventional fluid possesses. We go on to show that the metafluid obeys the Einstein relation, which relates many-body response (viscosity) to single-particle dynamics (diffusion) and is a fundamental result in equilibrium thermal systems. Thus, our metafluid is wholly consistent with equilibrium thermal physics, despite being markedly nonequilibrium. Taken together, our results demonstrate a type of material that retains equilibrium physics while simultaneously allowing for direct programmatic control over material properties.
Materials Science Institute, University of Oregon, Eugene, OR 97403; Department of Physics, University of Oregon, Eugene, OR 97403 kwelch@uoregon.edu.
Kyle J
KJ
Welch
Materials Science Institute, University of Oregon, Eugene, OR 97403; Department of Physics, University of Oregon, Eugene, OR 97403.
Alexander
A
Liebman-Peláez
Materials Science Institute, University of Oregon, Eugene, OR 97403; Department of Physics, University of Oregon, Eugene, OR 97403.
Eric I
EI
Corwin
Faraday waves; emergent thermodynamics; metafluid