OPTICAL CHARACTERISTICS OF ELECTRORHEOLOGICAL AND ELECTROMAGNETORHEOLOGICAL FLUIDS

The optical character of electrorheological (ER) and electro-magnetorh eological (EMR) fluids under the influence of an external field are in vestigated. It is found that the transmission of ER fluids could be ad justed through selecting the proper electric field and suspension conc entration. The IR spectral transmissions of ER fluids increase with an applied electric field. The maximum transmittance for low-concentrati on fluid changed from 4% to 23%. It is also observed that the window o f transmission does not change with fluid consistency and external ele ctric field. We find that the scattering patterns of ER fluids consist of the many bright and dark bands as a scattering grating. The widths of bright bands increase with increasing electric field. The scatteri ng pattern of EMR fluids under electric and magnetic fields superimpos ed in the perpendicular is also observed. These phenomena provide new mechanics for the design of tunable optical devices and will have dire ct industrial application, (C) 1998 Society of Photo-Optical Instrumen tation Engineers. [S0091-3286(98)01605-5].