Search for: All records

A simple and facile method was developed to fabricate functional bulk barium titanate (BaTiO₃,BT) ceramics using the paste extrusion 3D printing technique. TheBTceramic is a lead‐free ferroelectric material widely used for various applications in sensors, energy storage, and harvesting. There are several traditional methods (eg, tape casting) to process bulkBTceramics but they have disadvantages such as difficult handing without shape deformation, demolding, complex geometric shapes, expansive molds, etc. In this research, we utilized the paste extrusion 3D printing technique to overcome the traditional issues and developed printable ceramic suspensions containingBTceramic powder, polyvinylidene fluoride (PVDF), N,N‐dimethylformamide (DMF) through simple mixing method and chemical formulation. ThisPVDFsolution erformed multiple roles of binder, plasticizer, and dispersant for excellent manufacturability while providing high volume percent and density of the final bulk ceramic. Based on empirical data, it was found that the maximum binder ratio with good viscosity and retention for desired geometry is 1:8.8, while the maximumBTcontent is 35.45 vol% (77.01 wt%) in order to achieve maximum density of 3.93 g/cm³(65.3%) for 3D printedBTceramic. Among different sintering temperatures, it was observed that the sinteredBTceramic at 1400°C had highest grain growth and tetragonality which affected high performing piezoelectric and dielectric properties, 200 pC/N and 4730 at 10³ Hz respectively. This paste extrusion 3D printing technique and simple synthesis method for ceramic suspensions are expected to enable rapid massive production, customization, design flexibility of the bulk piezoelectric and dielectric devices for next generation technology.

An electric field‐assistedin situdispersion of multiwall carbon nanotubes (MWCNTs) in polymer nanocomposites, fabricated through stereolithography three‐dimensional (3D) printing technique, was demonstrated. The introduction of MWCNTs increased the elasticity modulus of the polymer resin by 77%. Furthermore, the use of an electric field forin situMWCNT dispersion helped improving the average elongation at break of the samples with MWCNTs by 32%. The electric field also increased the ultimate tensile strength of the MWCNT reinforced nanocomposites by 42%. An increase of over 20% in the ultimate tensile strength ofin situdispersed MWCNT nanocomposites over the pure polymer material was observed. Finally, it was demonstrated that the magnitude and direction of the electrical conductivity of MWCNT nanocomposites can be engineered through the application ofin situelectric fields during 3D printing. An increase of 50% in the electrical conductivity was observed when MWCNTs were introduced, while the application of the electric field further improved the electrical conductivity by 26%. The presented results demonstrated the feasibility of tuning both electrical and mechanical properties of MWCNT reinforced polymer nanocomposites usingin situelectrical field‐assisted 3D printing. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47600.