Active sieving and separation of particles
In Nature, exceptional permeability and selectivity properties are reached in ion channels. The paradigm change as compared to nanoscale technology is that these biological filters are out-of-equilibrium, submitted to either thermal or active fluctuations – for example of the pore constriction. We investigated how out-of-equilibrium fluctuations of a pore affects translocation dynamics, and found regimes of enhanced selectivity and transport. These results open up the possibility that transport across membranes can be actively tuned by external stimuli, with potential applications to nanoscale pumping, osmosis and dynamical ultrafiltration.
Water transport at the nanoscale
Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates, yet the exact mechanism of transport inside nanotubes continues to be debated because of the limited number of experimental results. We have met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Our measurements reveal large and radius-dependent surface slippage in carbon nanotubes (and not in their insulating counterpart, boron nitride nanotubes). This emphasizes that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.