Evaluation of Lateral and Vertical Dimensions of Micromolds Fabricated by a PolyJet™ Printer

Abstract

PolyJet™ 3D printers have been widely used for the fabrication of microfluidic molds to replicate castable resins due to the ease to create microstructures with smooth surfaces. However, the microstructures fabricated by PolyJet printers do not accurately match with those defined by the computer-aided design (CAD) drawing. While the reflow and spreading of the resin before photopolymerization are known to increase the lateral dimension (width) of the printed structures, the influence of resin spreading on the vertical dimension (height) has not been fully investigated. In this work, we characterized the deviations in both lateral and vertical dimensions of the microstructures printed by PolyJet printers. The width of the printed structures was always larger than the designed width due to the spreading of resin. Importantly, the microstructures designed with narrow widths failed to reproduce the intended heights of the structures. Our study revealed that there existed a threshold width (wd′) required to achieve the designed height, and the layer thickness (a parameter set by the printer) influenced the threshold width. The thresholds width to achieve the designed height was found to be 300, 300, and 500 μm for the print layer thicknesses of 16, 28, and 36 μm, respectively. We further developed two general mathematical models for the regions above and below this threshold width. Our models represented the experimental data with an accuracy of more than 96% for the two different regions. We validated our models against the experimental data and the maximum deviation was found to be <4.5%. Our experimental findings and model framework should be useful for the design and fabrication of microstructures using PolyJet printers, which can be replicated to form microfluidic devices.

Advancing 3D printed microfluidics with computational methods for sweat analysis

“…As an example, polydimethylsiloxane (PDMS) is a widely used elastomer in microfluidics due to its inertness, robust structure, and transparency, which is conventionally utilized with soft lithography for microfluidic fabrication [ 55 ]. 3D printing enables the fabrication of PDMS either directly or as a mold [ 59 ]. The 3D printing for PDMS as a mold is reported down to a 10-µm feature resolution [ 60 ].…”

A review on polyjet 3D printing of polymers and multi-material structures

“…Hence, a novel approach is needed to be developed to demonstrate the capability of the model. Moreover, the formation of temperature gradients while the polyjet is printing the structures, 171,172 the development of large residual stresses in fabricated structures, 49,173 and poor interlayer adhesion among the 3D printed layers 174 limits the functionality of photopolymer jetting printing. The polyjet AM technique builds components layer by layer while curing the photopolymer resin, resulting in a temperature gradient.…”

Wettability and Surface Roughness of Parylene C on Three-Dimensional-Printed Photopolymers

“…Hull developed the first stereolithography (SLA) technology and patented the first 3D printer [5]. Current commercial 3D printers are based on various technologies, including liquid-based 3D printing technologies, such as SLA, digital light projection (DLP), inkjet printing, and PolyJet [6][7][8][9]; filament-or paste-based 3D printing technologies, such as fused deposition (FDM), 3D dispensing, robocasting, and laminated object manufacturing [10][11][12][13]; and powder-based 3D printing technologies, such as selective laser sintering, selective laser melting, electron beam melting, 3D powder binding, and laser engineered net shaping [14][15][16][17][18]. These technologies meet various types of user requirements.…”