In this study, chemical composition, structural and physical properties of expanded perlite (EP) were determined by particle size, apparent density, SEM-EDS and XRD measurements. Electrorheological (ER) properties of EP particles dispersed in silicone oil (SO) were fully investigated as a novel dry-based ER fluid. Thus, ER response of EP/SO dispersions was revealed as a function of electric field strength (E), volume fraction, shear rate, shear stress, frequency and temperature. As a result, the EP/SO ER fluid was observed to sensitive to external E, exhibiting a typical shear thinning non-Newtonian viscoelastic behavior. The correlation between the yield stress (tau(y)) and E was deviated from polarization model (m < 2). Further, antisedimentation stabilities of the mesoporous EP particles in SO medium were determined to be perfectly suitable for potential ER applications under various temperatures. (C) 2017 Elsevier Inc. All rights reserved.