ER fluid based on inorganic/polymer blend particles and its adaptive viscoelastic properties

Electrorheological fluid (ERF) is one of the most favorite actuator materials used in smart materials and structures due to its fast, reversible, controllable and continuous change of rheological properties. In the present paper, a new kind of ERF based on silica carried lithium salt of phenolic polymer particles dispersed in silicon oil is developed. This kind of ERF performs good ER activity. The yield stress is about 1900Pa while the electric field strength is 3.2 kV mm(-1) and the current density is less than 8 muA cm(-2). The viscoelastic properties of this ERF are investigated experimentally by both the steady shear and dynamic test while the electric field strength range is 0-5 kV mm(-1). ERF behaves adaptive viscoelasticity while the control parameter is the electric field strength. External electric field can change ERF's shear modulus effectively. With an external electric field, ERF shows not only linear viscoelastic properties but also non-linear viscoelastic properties. The viscoelastic parameters such as creep compliance and shear modulus depend on external electric field strength, the amplitude of shear force, as well as the shear force frequency. (C) 2001 Elsevier Science B.V. All rights reserved.