Influence of tool fabrication process on characteristics of hot embossed polymer microfluidic chips for electrospray

摘要

Fabrication techniques for mass manufacture of disposable polymer microfluidic chips are important for electrospray application used in mass spectrometry. Hot embossing offers advantages over traditional MEMS fabrication techniques and is the focus of this research. The aim of the paper is to evaluate hot embossed open channel polymer chips using two different hot embossing tools. One tool was fabricated in nickel using the electroforming process, and the other in high carbon bright steel by laser machining technique using a pulsed Nd:YAG laser that is normally used for conventional applications. Process parameters are determined and measurement of dimensions and surface roughness of tools and chips are presented. Depending on the fabrication method, each tool exhibits its own characteristic profile feature and surface roughness. Polystyrene and polycarbonate substrates embossed with the electroformed tool exhibited lowest surface roughness of 48 nm compared to 450 nm for the laser machined tool. The embossed microfluidic chips were tested for fluid flow and electrospray and showed good performance.