High-pressure needle interface for thermoplastic microfluidics

Abstract

A robust and low dead volume world-to-chip interface for thermoplastic microfluidics has been developed. The high pressure fluidic port employs a stainless steel needle inserted into a mating hole aligned to an embedded microchannel, with an interference fit used to increase pressure resistance. Alternately, a self-tapping threaded needle screwed into a mating hole is also demonstrated. In both cases, the flat bottom needle ports seat directly against the microchannel substrate, ensuring low interfacial dead volumes. Low dispersion is observed for dye bands passing the interfaces. The needle ports offer sufficient pull-out forces for applications such as liquid chromatography that require high internal fluid pressures, with the epoxy-free interfaces compatible with internal microchannel pressures above 40 MPa.

Lab-on-a-chip devices: How to close and plug the lab?

“…Other insertion-based fluidic connections were used for plastic microfluidic chips. For example, Chen et al reported pressure capabilities as high as 40 MPa using a threaded stainless steel needle inserted into a COC chip [162].…”

Optical detection enhancement in porous volumetric microfluidic capture elements using refractive index matching fluids

“…Fluidic interfaces for off chip syringe pumps were created by inserting needle tubing segments into the access ports following a previously reported method 11 after the packed bed was formed. Fluidic fittings were attached to the needles and tests were conducted immediately.…”

Polymeric-Based In Vitro Diagnostic Devices

“…Pressure is vitally important because it ensures complete contact between bonding surfaces and eliminates the possibility of voids or deformation. If created under optimized conditions, sealed polymer sheets can withstand pressures greater than 20 MPa without delamination [121]. Notably, a novel solvent vapor treatment has been used to irreversibly bond PMMA and COC chips while simultaneously reducing the channel surface roughness and yielding optical grade, which is less than 15 nm surface roughness on the channel walls ( Fig.…”

“…Solvent bonding is another bonding technique especially suited for polymer IVD devices that require high bond strengths [121]. The bonding process includes b Design and image of assembled, 10-layer assay card.…”