Utilization of Polymer-Nanoparticle Composite in Micro-Stereolithography 3D Printing

Advances in micro-stereolithography (µ-SL) 3D printing enable the fabrication of complex microstructures for biomedical, energy and other applications. However, the narrow selection of optical-curable printing materials limits its wide deployment. 3D printed micromodels are used to mimic the morphology of natural rock and reveal the microfluidic flow physics for subsurface energy application, but the surface chemistry of the printed polymer micromodel are totally different from natural rock surface. Therefore, polymer-based composites are used to tailor intrinsic properties, such as mechanical strength and surface wettability. In this work, we utilize the composite of polymer and calcite nanoparticle in a high-resolution µ-SL 3D printing system. Light scattering induced by the nanoparticles and its influence on printing resolution are analyzed under various particle sizes and concentrations. The transparency of printed micromodels reduces accordingly, which would affect the microfluidic flow imaging performance. Surface wettability conditions, including the contact angle and its hysteresis, are also characterized. This study provides important guidance in the utilization of polymer/nanoparticle composite in µ-SL 3D printing for broad microfluidic applications.