Cyclic olefin copolymer as an X-ray compatible material for microfluidic devices

Abstract

The combination of microfluidics and X-ray methods attracts a lot of attention from researchers as it brings together the high controllability of microfluidic sample environments and the small length scales probed by X-rays. In particular, the fields of biophysics and biology have benefited enormously from such approaches. We introduce a straightforward fabrication method for X-ray compatible microfluidic devices made solely from cyclic olefin copolymers. We benchmark the performance of the devices against other devices including more commonly used Kapton windows and obtain data of equal quality using small angle X-ray scattering. An advantage of the devices presented here is that no gluing between interfaces is necessary, rendering the production very reliable. As a biophysical application, we investigate the early time points of the assembly of vimentin intermediate filament proteins into higher-order structures. This weakly scattering protein system leads to high quality data in the new devices, thus opening up the way for numerous future applications.

The Fabrication and Application Mechanism of Microfluidic Systems for High Throughput Biomedical Screening: A Review

“…The fields of biophysics and biology have benefited enormously from such approaches. A general approach of screening for crystal growth and data collection is to use a combination of COC and PDMS to allow the inclusion of a microfluidic valve and use silane to bond the layers [33][34][35][36][37]. Some other researchers use COC to fabricate an all-COC device.…”

“…Denz et al, using soft lithography, produced a channel structure that was established using an all-COC microfluidic device to measure X-ray inflow with high throughput. They investigated the early time points of the assembly of vimentin intermediate filament proteins into higher-order structures using the aforementioned system [37]. A perfluoropolyether (PFPE) biochip was built to culture and analyze the cells of liver and kidney (shown in Figure 1B).…”

Vesicle adhesion in the electrostatic strong-coupling regime studied by time-resolved small-angle X-ray scattering

“…X-ray compatible microfluidic devices were built in a multi-step process following the protocol in ref. 31. First, SU-8 2150 negative photo resist (MicroChem, Newton, MA, USA) is processed by means of standard photolithography on a 2-inch silicon wafer.…”

Multiscale X-Ray Analysis of Biological Cells and Tissues by Scanning Diffraction and Coherent Imaging

“…In this respect, three basic concepts are generally followed: (i) static chambers that typically consist of two windows glued together and containing a small, microlitersized amount of liquid (see e.g. [164]), (ii) microfluidic chambers [165,166], and (iii) jet or droplet injection systems [70].…”

“…While liquid jet and droplet technology (aerosol jets) are already quite advanced and have paved the way for studies of smaller, identical particles such as viruses wrapped in a thin hydrated shell [160,214], sample delivery of non-identical particles such as larger colloids, bacteria or eukaryotic cells [162,163] require a different approach, both in terms of cross section of the delivery system as well as in view of a need for pre-screening of the object, and eventual rotation and positioning. To this end, channel microfluidics can be made compatible with X-ray experiments using suitable thin foil window materials, as reviewed in [165] and [166]. As far as trapping, positioning and rotation are concerned, optical forces are the tool of choice to manipulate an individual particle, for example in a channel with or without flow, and to prevent the particle or cell from diffusing out of focus.…”