Mesoporous Thin Films for Fluid Manipulation

Abstract

The ability to control nanoflows is critical to design and fabricate ever more versatile nanosystems. Scientists are currently interested in finding ways to handle fluid dynamics inside nanoporous networks, not only to increase our knowledge of fluidic behavior but also to develop novel nanodevices that have potential utility in applications ranging from diagnostics to the production of high-value chemicals. Here, we demonstrate how fluid motion can be manipulated by controlling the coexisting infiltration and evaporation phenomena in mesoporous films. A versatile actuation approach through liquid?vapor dynamic modulation was developed by integrating mesoporous substrates with a thermoelectric cell. This actuation resulted in fast and reversible fluid displacements through the mesoporous matrix, which was achieved with relatively small temperature variations by controlled voltage inputs. The versatility of the strategy is demonstrated by tunable cycling of fluid imbibition and switched nanofluidic connection of liquids into the substrate. This novel nanoflow manipulator could be the basis for smart nanofluidic devices toward exciting applications in actuators, controlled pattern formations and release systems.