Piezoelectric thick film fabricated with aerosol deposition and its application to piezoelectric devices

The aerosol deposition (AD) method is a unique approach to metal and ceramic coating, by which solid-state submicron metal and ceramic particles are accelerated by gas flow up to 100-500 m/s and then impacted onto a substrate. The National Institute of Advanced Industrial Science and Technology (AIST) found an interesting consolidation phenomenon of ceramic particles in this method over 20 years ago. During the collision of fine particles and interaction with the substrate, these ceramic particles, not only for oxide materials but also for non-oxide materials, form thick, dense, and hard ceramic layers at room temperature. No additional heating for the solidification of ceramic powder was required. We named this phenomenon "room-temperature impact consolidation (RTIC) . Consolidated ceramic powder with RTIC via the AD method can be called as a high-density binderless ceramic green. It can rapidly form into a thick dense, uniform, and hard layer at room temperature without additional heating for solidifying starting powders, even at a low vacuum, using relatively cheap and simple production facilities. Metal-based optical scanning devices, tube-type ultrasonic motors, and piezoelectric energy harvesters are fabricated by the AD method have been developed for sensor and actuator applications.