  Nanofluidics, the field interested in flows at the smallest scales, has grown
at a fast pace, reaching an ever finer control offluidic and ionic transport at
the molecular level. Still, artificial pores are far from reaching the wealth
of functionalities of biological channels that regulate sensory detection,
biological transport and neurostransmission - all while operating at energies
comparable to thermal noise. Here, we argue that artificial ionic machinescan
be designed by harnessing the entire wealth of phenomena available at the
nanoscales and exploiting techniques developped in various fields of physics.
As they are generally based on solid-state nanopores, rather than soft
membranes and proteins, they should in particular aim at taking advantage of
their specific properties such as their electronic structure or their ability
to interact with light. These observations call for the design of new ways of
probing nanofluidic systems. Nanofluidics is now at the crossroads, there are
new avenues to build complex ionic machines and this may allow to develop new
functionalities inspired by Nature.
