This work studies the strain response of lead magnesium niobate-lead titanate (0.9PMN-0.1PT) multilayer actuators for industrial automation applications. Since the 0.9PMN-0.1PT is relaxor-based ferroelectric material, its piezoelectricity can be induced by applying a DC bias field longitudinally across the actuator structure. A 7.3 mum displacement in the longitudinal direction was produced by a 9.034 mm long multilayer actuator under a DC bias voltage of 185 V. Effective piezoelectric coefficients d(33) and d(31) of the 0.9PMN-0.1PT actuator were estimated by the derivative of the strain vs. electric field curve. It was found that deformation of the actuator near the edge on the top surface is about 17% lower than the deformation at the center. (C) 2002 Published by Elsevier Science B.V.