This paper presents the design, fabrication and characterization of magnetic particle incorporated composite polydimethylsiloxane (PDMS) membrane actuators for microfluidic applications. Circular composite membranes with different diameters have been prepared with three different types of magnetic particles; lauric acid coated superparamagnetic iron-oxide nanoparticles (SPION-LA), lauric acid coated carbonyl iron microparticles (CI-LA), and pristine carbonyl iron microparticles (CI). Fabricated composite membranes' deflections were tested with a NdFeB permanent magnet. The maximum membrane deflection values were characterized with respect to the membrane diameters and membrane composition and the results were compared with theoretical analysis. CI microparticles incorporated composite membranes have given the largest deflection values among the membranes fabricated with a maximum deflection of 762 mu m at 0.27 mT for the membrane 6.2 mm in diameter.