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In this article, we present OSTE+RIM, a novel reaction injection molding (RIM) process that combines the merits of off-stoichiometric thiol–ene epoxy (OSTE+) thermosetting polymers with the fabrication of high quality microstructured parts. The process relies on the dual polymerization reactions of OSTE+ polymers, where the first curing step is used in OSTE+RIM for molding intermediately polymerized parts with well-defined shapes and reactive surface chemistries. In the facile back-end processing, the replicated parts are directly and covalently bonded and become fully polymerized using the second curing step, generating complete microfluidic devices. To achieve unprecedented rapid processing, high replication fidelity and low residual stress, OSTE+RIM uniquely incorporates temperature stabilization and shrinkage compensation of the OSTE+ polymerization during molding. Two different OSTE+ formulations were characterized and used for the OSTE+RIM fabrication of optically transparent, warp-free and natively hydrophilic microscopy glass slide format microfluidic demonstrator devices, featuring a storage modulus of 2.3 GPa and tolerating pressures of at least 4 bars., QC 201500618

QC 20130521, Rappid

In this work we have developed a simple and robust method to permanently pattern alternating hydrophobic and hydrophilic surfaces in off-stoichiometry thiol-ene (OSTE) polymer microchannels. By being able to tune the number of unreacted thiol surface groups of the OSTE Thiol polymers and by taking advantage of spatially photo-controlled surface grafting of methacrylate monomers we achieve defined areas with contact angles from 20° to 115° within one single channel. The surface modification remains stable after storage in air (>2 months) or water (>24h)., QC 20121120

QC 20130521, RPA, Rappid

To fabricate complex microfluidic devices in a rapid manner, we have developed a novel method for simultaneous patterning of two sides of a single layer of PDMS using double-sided micromoulding. A mould surface coating containing aminosilanised poly(vinyl alcohol) (PVA) provides low-stress release of fragile polymer structures from the mould as well as inhibition of PDMS polymerisation at through-hole locations, thus enabling fabrication of membranes and 3D microfluidic networks in a single step. Alignment of the top and bottom patterns is achieved already during the moulding step using guiding structures in the mould halves, leading to a procedure with a minimum number of alignment and bonding steps needed to fabricate fragile 3D microfluidic devices., QC 20130110. QC 20160314

We propose and demonstrate a novel one step method to integrate gold coated sensors with cartridges by dry covalent bonding. The cartridges are replica molded in an UV-curable off-stoichiometry thiol-ene (OSTE) polymer, featuring an excess of thiol functional groups that covalently bond to the surface of gold coated sensors upon contact. The method is demonstrated by the integration of a gold coated quartz crystal to a microfludic OSTE cartridge. The resulting bond interface is shown to be completely homogenous and void free and the package is tested successfully to a differential pressure of up to 2 bars. The performance of the biosensor chip is evaluated by measuring the unspecific binding of 0.5% albumin, resulting in a total frequency drop 205 Hz. This approach delivers a simple but rapid high quality integration aiming for the production of robust, low cost and disposable biosensor chips, QC 20111129, RPA, Rappid

Point-of-care diagnostic devices typically require six distinct qualities: they must deliver at least the same sensitivity and selectivity, and for a cost per assay no greater than that of today's central lab technologies, deliver results in a short period of time (<15 min at GP; <2h in hospital), be portable or at least small in scale, and require no or extremely little sample preparation. State-of-the-art devices deliver information of several markers in the same measurement., QC 20110509

QC 20111129, Rappid