3D Printing Solutions for Microfluidic Chip-To-World Connections

Abstract

The connection of microfluidic devices to the outer world by tubes and wires is an underestimated issue. We present methods based on 3D printing to realize microfluidic chip holders with reliable fluidic and electric connections. The chip holders are constructed by microstereolithography, an additive manufacturing technique with sub-millimeter resolution. The fluidic sealing between the chip and holder is achieved by placing O-rings, partly integrated into the 3D-printed structure. The electric connection of bonding pads located on microfluidic chips is realized by spring-probes fitted within the printed holder. Because there is no gluing or wire bonding necessary, it is easy to change the chip in the measurement setup. The spring probes and O-rings are aligned automatically because of their fixed position within the holder. In the case of bioanalysis applications such as cells, a limitation of 3D-printed objects is the leakage of cytotoxic residues from the printing material, cured resin. This was solved by coating the 3D-printed structures with parylene-C. The combination of silicon/glass microfluidic chips fabricated with highly-reliable clean-room technology and 3D-printed chip holders for the chip-to-world connection is a promising solution for applications where biocompatibility, optical transparency and accurate sample handling must be assured. 3D printing technology for such applications will eventually arise, enabling the fabrication of complete microfluidic devices.

3D-Printed Chips: Compatibility of Additive Manufacturing Photopolymeric Substrata with Biological Applications

“…To reduce leaching, Macdonald et al [ 13 ] experimented with coating SLA printed parts with wax and found that the coating was only effective at delaying the onset of toxicity (by ∼40 h). The authors of van den Driesche et al [ 118 ] removed the toxicity of parts printed by DLP in resins, E-Shell 300 and HTM140, by coating them in parylene-C, which is an ultra-thin biocompatible polymer coating. Coating parts with biocompatible hydrogels (e.g., PEG-DA) or PDMS may also be an effective strategy to remove toxicity of easily accessible photopolymeric resins.…”

Fast Formation of Lipid Bilayer Membranes for Simultaneous Analysis of Molecular Transport Using Parylene Coated Chips

“…40 µL), compatible with standard industrial pipetting robots. The mounting method for the bilayer chips is depicted in Figure 2a [3]. The chip is mounted in a chip slot located in a 3D printed holder (Part-1).…”

Application of Microfluidic Chip Technology in Food Safety Sensing

“…The laser ablation here specifically refers to a method of ablating and machining a micro flow channel on the surface of a polymer material by using a carbon dioxide laser with a wavelength of 10.6 µm [24].…”