Fabrication of Piezoelectric Ceramic/Polymer Composite Transducers Using Fused Deposition of Ceramics

Abstract

The fused deposition of ceramics (FDC) technique was used to fabricate piezoelectric ceramic skeletons for the development of piezoelectric composite transducers with 2-2 connectivity for medical imaging. The green parts were designed to have 30 vol% lead zirconate titanate ceramic (PZT-5H) in the final composites. Physical characterization of the sintered samples revealed that 96% of the theoretical density was achieved. Optical microscopy showed that defects due to the FDC mode of deposition, such as small roads and bubbles, were eliminated, because of improvements in powder processing. The electromechanical properties of the final composites were similar to the properties that were obtained for conventionally made composites. A matching layer and a backing layer, as well as wires and an inductor, were added to each FDC composite to fabricate a functional medical imaging transducer. The devices were tested in water using a steel target 3.5 cm thick. Echoes from the target could be detected with all the transducers that were fabricated using FDC. The sensitivities of the transducers were similar to that of a commercial transducer. However, the ringing was much longer than that for a commercial transducer, because the backing layer was not optimized in the transducers that were fabricated using FDC.

Direct Ink Writing of 3D Functional Materials

“…[11] Several direct ink writing techniques have been introduced that are capable of patterning materials in three dimensions. They can be divided into filamentary-based approaches, such as robocasting [12,13] (or robotic deposition [4,7,14,15] ), micropen writing, [16] and fused deposition, [17,18] and droplet-based approaches, such as ink-jet printing, [19,20] and hot-melt printing [21] (see Fig. 1).…”

“…Many ink designs have been employed including highly shear thinning colloidal suspensions, [12,13,16] colloidal gels, [15,22] polymer melts, [17] dilute colloidal fluids, [20] waxes, [21,23] and concentrated polyelectrolyte complexes. [4,24,25] These inks solidify either through liquid evaporation, [12,13,19,20] gelation, [7,14,15] or a temperature- [17,18] or solvent-induced phase change. [4,24,25] Through careful control of ink composition, rheological behavior, and printing parameters, 3D structures that consist of continuous solids, high aspect ratio (e.g., parallel walls), or spanning features can be constructed.…”

Novel piezoelectric ceramic-polymer aligned composites via the freeze casting method for high frequency transducer applications

“…[2][3][4][5][6][7][8] In addition, these composites are not brittle like those single phase ceramics, so it could avoid crack formation during lapping down. To date, piezoelectric ceramic-polymer composites in different phase conductivity have been synthesized by various methods such as such as dice-and-fill technology, [2,3] injection moulding, [4] multiple molds route, [5] dielectrophoretic assembly, [6] tape casting [7] and fused deposition of ceramic (FDC) technique.…”

“…To date, piezoelectric ceramic-polymer composites in different phase conductivity have been synthesized by various methods such as such as dice-and-fill technology, [2,3] injection moulding, [4] multiple molds route, [5] dielectrophoretic assembly, [6] tape casting [7] and fused deposition of ceramic (FDC) technique. [8] Nevertheless, there is a common disadvantage that all these methods could be not suitable for mass production, because of the high costs or time-consuming operations.…”

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

“…These SFF methods have mostly been developed in the past for prototyping purposes and used in polymer systems, but have recently been extended to ceramic materials. Examples of these methods include ink jet printing [3], Robocasting [4], Fused Deposition of Ceramics [5] and other related methods (see [1,2] for a more complete overview). All these methods have clear advantages in terms of ease of production of complex shapes.…”