The behavior of colloidal suspensions of nanoscale ferromagnetic particles (~10 nm in size), with and without carrier fluid, will be investigated. Such flows, when driven or controlled by magnetic fields, can display a number of aspects of potential interest to practical applications of special interest are nano-electromechanical devices (NEMS). The PI plans to take a fundamental look at the following flows, in close cooperation with industrial partners:
1. Channel flows with a width of the order of 100-1000 nm: under alternating and traveling magnetic fields, they can achieve significant flow rates with only a moderate (or even reverse) effective viscosity. 2. Rotational motion can be applied to nanoparticles in a fluid-free medium by a suitable array of nanocoils on the surface of the channel. 3. The reverse effect, i.e. applying fluid force to particles, whose rotational motion will induce in turn an electric current into the nanocoils. 4. The fabrication of mechanical nanocomponents can be accomplished by using a material which is in the liquid state of high temperature, but in the solid state at room temperature. Thus it is possible to apply at high temperature the magnetic fields necessary to give the desired flow shape, and then freeze. Gear shapes seem to be an easy first step to test this technique. 5. The use of nonmagnetic fluids, or of surfactants, will be tested as way to reduce surface tension and therefore improve the detailed quality of the component shape.
There is a strong collaboration contemplated with the Ferrofluids Corporation, at both experimental/design levels.
