The fabrication of composite electromechanical devices for micromovement applications in manufacturing processes
The objectives of the project are to establish technologies for the fabrication of low voltage, high reliability, ultraprecise micromovement devices which utilise functional ceramic elements in multilayer configurations. Certain doped lead zirconate titanate (PZT) systems combine good electrical properties and electromechanical properties with ability to be cofired with silver palladium electrode systems. Chemically prepared materials show great promise for low firing temperature and very thin active layers. The major fabrication effort has been to develop ceramic tape casting with electrode screen printing. Multilayer screen printing of thick film pastes is a promising alternative technique. Experiments using laser ablation deposition have revealed difficulties in forming coherent electrode layers. Consolidation routes by conventional firing have been successfully established for laminated tape and multilayer screen printed forms. Laser ablation deposition structures have been successfully annealed. Routine electrical measurements and electromechanical measurements have been made on initial devices. Force measurements as a function of frequency and loading, and lifetime testing under load have been carried out. Finite element analysis has been used to compute 2 dimensional field distributions and stress distributions for sections in the vicinity of an electrode discontinuity. Applications of devices developed in this project range from automotive fuel injection valves to ink jet printer heads and cover micropositioning, machine tools, precision optics, etc.