Solid Freeform Fabrication of Piezoelectric Actuators by a Micro-Casting Method

In recent years, there has been much interest in the manufacturing of piezoceramic actuators by Solid Freeform Fabrication (SFF) methods, following developments in polymer and metal shaping. With these methods, actuator shapes can be realized that are impossible or very difficult to obtain by traditional ceramic shaping techniques. At TNO, research is currently performed on the development of technology to use SFF methods to develop multi-material components, i.e. combining polymers, ceramics and metals in one production process. One SFF-technique, which is investigated in this study, is micro-casting. In this process, a highly loaded ceramic suspension is deposited by a nozzle, attached to a computer-controlled positioning system. With this process, it is possible to make 3D components directly from CAD files, or to fill volumes using wider nozzles. As a case study, such a casting process was used to produce a piezo-electric bender and an ultrasonic transducer element.