3D printed metal molds for hot embossing plastic microfluidic devices

Abstract

Plastics are one of the most commonly used materials for fabricating microfluidic devices. While various methods exist for fabricating plastic microdevices, hot embossing offers several unique advantages including high throughput, excellent compatibility with most thermoplastics and low start-up costs. However, hot embossing requires metal or silicon molds that are fabricated using CNC milling or microfabrication techniques which are time consuming, expensive and required skilled technicians. Here, we demonstrate for the first time the fabrication of plastic microchannels using 3D printed metal molds. Through optimization of the powder composition and processing parameters, we were able to generate stainless steel molds with superior material properties (density and surface finish) than previously reported 3D printed metal parts. Molds were used to fabricate poly(methyl methacrylate) (PMMA) replicas which exhibited good feature integrity and replication quality. Microchannels fabricated using these replicas exhibited leak-free operation and comparable flow performance as those fabricated from CNC milled molds. The speed and simplicity of this approach can greatly facilitate the development (i.e. prototyping) and manufacture of plastic microfluidic devices for research and commercial applications.

A Review of Current Methods in Microfluidic Device Fabrication and Future Commercialization Prospects

“…While this is not anywhere near the hundreds of thousands of cycles capable on some metal mold inserts, this direction shows great promise as an up-and-coming or even a potentially game-changing technology in 3D printing. In a similar, yet unique take on addressing the challenge of high-cost mold fabrication, 3D printed metal molds show the potential for the rapid production of metal mold inserts [34]. As this technology is refined, it will likely see applications in mold fabrication.…”

“…The value of this technology is in its ability to reduce the cost of thermoplastic molding, making it more accessible by researchers and commercialization entities. In another recent publication, Lin et at present a 3D printed metal mold method for rapid production of metal mold inserts [34]. While metal 3D printing is still in its infancy, it will undoubtedly become more feasible as this technology develops.…”

3D‐Printed Biomaterials for Guided Tissue Regeneration

“…A variety of materials, including natural and synthetic polymers, ceramics, metals/alloys, and composites, have been 3D printed. Here, we categorize 3D‐printing technologies into three groups based on the morphology of the printable material feeds: bulk solids (e.g., fused deposition modeling (FDM) ( Figure A), fluids (e.g., direct ink writing (DIW), inkjet printing, stereolithography (SLA) (Figure B–D)), and particles (e.g., powder‐bed‐based selective laser sintering (SLS) (Figure E)).…”

Modeling and experimental investigation of polymer micropart demolding from a Zr‐based bulk metallic glass mold

“…The roughness of sample surface contact to the silicon mold dominates the replication quality of BMG micro‐mold. Moreover, the surface roughness of the molded polymer components plays an important role in bonding the finished chips to their cover plates . Therefore, the Zr‐based BMG samples were polished with SiC abrasive papers (400‐, 500‐, 800‐, 1,000‐, 1,200‐, 1,400‐, 1800‐ and 2000‐grit; Wuxi Gangxia Precision Abrasive Paper Co., Ltd., China).…”