The response times of ER suspensions

Since the ER effect is determined by the Wagner-Maxwell polarization, the response time of the ER suspensions should be identical to the relaxation time of the Wagner-Maxwell polarization. That is, for a system where the conductivity of tlie dispersed particle is much larger than that of the dispersed medium and the conduetivity contribution from the dispersed medium is negligible, the relaxation time can be described by a simplified form as shown in Eq. (144) in Chapter 7. 

However when the conductivity of the dispersed medium is large enough in 

The experimental evidences for supporting Cq. (76) or (77) are given previously. Eq. (77) and (78) provide a means for controlling the response time of ER fluids. 

7 DIELECTRIC PROPERTY OF ER FLUIDS UNDER A HIGH ELECTRIC FIELD 

Besides dielectric constant, the dielectric loss also increases with the applied electric field strength substantially for polyurethane particle/silicone oil ER suspension [67]. 

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