Development of tube actuators by fused deposition of ceramics

Fused Deposition of Ceramic (FDC) technique has been employed to fabricate piezoelectric tube arrays, based on the lead zirconate titanate system directly from a Computer-Aided Design (CAD) file. Extruded filaments with a diameter of 1.75 mm and 52.5 to 60 vol.% PZT loaded were used as feed material. Single tubes and tube arrays of up to 25 elements with the dimensions of 3 to 8 mm outer diameter, 6 to 20 mm height, and 0.4 to 2.0 mm wall thickness have been made. The green structures were subjected to a binder burnout to remove the organic material and were sintered at 1285/spl deg/C for 1 hour to 94-96% theoretical density. The electromechanical properties were evaluated in terms of axial displacements, resonance behavior and hysteresis. The effective piezoelectric coefficient in the axial direction was measured to be /spl sim/1,800 pm/V. The results demonstrate that the FDC technique can be used for rapid prototyping tube actuators with good electromechanical properties, thereby widening the scope of their application.