S. Liu, W. Wang, L. Liu, X. Chen
Arizona State University,
Keywords: additive manufacturing, μCLIP, piezoelectric composites, wearable sensing
Summary:Piezoelectric materials and composites enable a wide range of energy harvesting and sensing applications owning to their intrinsic capability of converting mechanical energy to electrical energy and vice versa. Additive manufacturing (AM), also known as 3D printing, is thriving as a category of effective and robust techniques in manufacturing three-dimensionally (3D) architected piezoelectric composites comprising of inorganic/organic piezoelectric materials, and these architected structures possess the potential of delivering anisotropic piezoelectric responses upon specific structural designs. Nonetheless, the serial nature of the additive building processes results in the inherent speed-accuracy trade-off, which seriously limits the scalability and efficiency of manufacturing functional devices that require precise control of fine features. As a result, the reported progress in this field either limit themselves to macroscale devices due to relatively low printing resolution, e.g, fused deposition modeling (FDM), or require extensive amount of fabrication time, e.g., projection micro- stereolithography (PμSL). On the contrary, micro continuous liquid interface production (μCLIP), a recently developed 3D printing technology, has been shown to create 3D geometries at very high speeds, with good surface finish, and uniform mechanical properties. Herein, we report rapid 3D printing of architected barium titanate (BTO) composite structures with high resolution by using μCLIP. The BTO nanoparticles were surface functionalized to enable stable dispersion in poly(ethylene glycol) diacrylate (PEGDA). Resins with up to 30 wt% of functionalized-BTO (f-BTO) nanoparticles were prepared and printed continuously to yield a variety of architected structures with unprecedented longitudinal printing speeds of up to ~ 20 μm/s. The architected structures were tested with a customized piezoelectric characterization setup and demonstrate effective piezoelectric coefficient d33 up to 30 pC N-1 and piezoelectric voltage constant g33 up to 460 mV mN-1 which is comparable to other reported work. This work not only enables the rapid 3D printing of architected piezoelectric structures with tailorable properties via compositional and structural modifications, but also intrinsically enlightens its potential capability for eco- and biocompatible applications.