2015 Volume 43 Issue 3_4 Pages 113-117
We measured electrorheological (ER) properties of suspensions of titanium dioxide/polymer composite particles using electrodes with regularly arranged fine projections. For a 10 wt% suspension, particles assembled between projections of electrodes and the yield stress became higher than the case of flat electrodes. On the other hand, the ER effect of a suspension with 30 wt% particles between pattern electrodes became weaker than between flat electrodes. From the observation of column structures of particles in a dilute (5 wt%) suspension between pattern electrodes, particles assembling between mountain sections of projections and thick columns were created. In the case of a dense (30 wt%) suspension, the space between flat and pattern electrodes was jammed with particles but several cracks were observed between valley sections on pattern electrodes. It is supposed that this difference is caused by the competition between the thick columns of mountain sections and low particle concentration regions between valley sections of pattern electrodes.
