The ability of ferrofluids to exhibit negative viscosities has implications for the selection of ferrofluids
used in the Meyer mechanical drive EPG as well as the linear magnetic drive systems.
Although there are viscosity measurements provided by the manufacturer of the EFH series ferrofluids and
it was postulated that the selection of the EFH -1 over the then available EFH- 4 which had a greater viscosity
(but also a higher percent of magnetite and magnetic susceptibility) was primarily given a greater importance
then magnetic susceptibility as a design factor.
If ferrofluids have a lower viscosity under an alternating magnetic field this observation might allow the use of
higher viscosity ferrofluids than those used by Stanley A Meyer
A possible effect of the alignment coils in the mechanical pump EPG design may be to reduce the viscosity
of the ferrofluid before and after pumping. There are also implications for the velocity of gaseous magnetic
matrices in the multi-tier series of EPG which used linear magnetic pumps.
see attachment or internet search for "negative viscosity of ferrofluid under alternating magnetic field"