LAUSR

The permittivity response from 0.5 to 40 GHz of ethyl acetate (C₄H₈O₂), ethylene glycol (CH₂OH)₂, castor oil (C₅₇H₁₀₄O₉), liquid paraffin, and other fluids commonly used for microwave microfluidic antennas and circuits is reported. The response of selected polymer solids, such as polydimethylsiloxane (PDMS), acrylonitrile butadiene styrene (ABS), acrylic, nylon, and others, used in microfluidics and 3-D printing of microwave structures was also studied from 0.5 to 20 GHz. Permittivity measurements were taken with a coaxial probe. Using a nonlinear least-squares fitting routine, the Cole–Cole dielectric relaxation model parameters are found for each material under test, thereby providing an analytic expression for their permittivity response.