Synthetic Microfluidic Paper consists of slanted and interlocked polymer micropillars and can be used as a porous substrate in microfluidics and lateral flow assays. We here demonstrate single step manufacturing of multiple Synthetic Microfluidic Paper densities in the same device, and passive alignment of liquid spots in denser substrate regions, regardless of spotting position, allowing increased control of receptor positioning for lateral flow assays. We further demonstrate that the transparency of Synthetic Microfluidic Paper allows increasing readout signal intensity with increasing substrate thickness, to a value 3 times larger compared to nitrocellulose substrates.
We present a Rubbery, Off-Stoichiometric Thiol-Ene-epoxy (OSTE+) polymer for direct lithography manufacturing, demonstrate its use in pneumatic pinch microvalves for lab-on-chip applications, test the lithography process achieving pillars of aspect-ratios (a.r.) 1:8, and characterize it’s surface as hydrophilic.
We introduce a polymer synthetic microfluidic paper for lateral flow devices. The aim is to combine the high surface area of paper, or nitrocellulose, with the repeatability, controlled structure, and transparency of polymer micropillars. Our synthetic paper consists of a dense, high aspect ratio array of transparent pillars that are slanted and mechanically interlocked. We describe the manufacturing using multidirectional UV lithography and demonstrate successful capillary pumping of whole blood.
We introduce Synthetic Microfluidic Paper, a novel porous material for microfluidic applications that consists of an OSTE polymer that is photostructured in a well-controlled geometry of slanted and interlocked micropillars. We demonstrate the distinct benefits of Synthetic Microfluidic Paper over other porous microfluidic materials, such as nitrocellulose, traditional paper and straight micropillar arrays: in contrast to straight micropillar arrays, the geometry of Synthetic Microfluidic Paper was miniaturized without suffering capillary collapse during manufacturing and fluidic operation, resulting in a six-fold increased internal surface area and a three-fold increased porous fraction. Compared to commercial nitrocellulose materials for capillary assays, Synthetic Microfluidic Paper shows a wider range of capillary pumping speed and four times lower device-to-device variation. Compared to the surfaces of the other porous microfluidic materials that are modified by adsorption, Synthetic Microfluidic Paper contains free thiol groups and has been shown to be suitable for covalent surface chemistry, demonstrated here for increasing the material hydrophilicity. These results illustrate the potential of Synthetic Microfluidic Paper as a porous microfluidic material with improved performance characteristics, especially for bioassay applications such as diagnostic tests.