Design and Fabrication of a Multi-Scale Fluidic Motherboard for a Universal Molecular Processing System (uMPS)

Abstract

A multi-scale fluidic motherboard, which can be used in a universal molecular processing system (uMPS) integrated with task-specific processing modules, was designed and fabricated in thermoplastics. The motherboard consists of a coverplate and a substrate. The coverplate included fluidic interconnects and thermal grooves on the top side, and the corresponding interconnects on the bottom side. The substrate was comprised of cell lysis microchannels, micromixers, and flow-connecting microchannels on the top side, and reservoirs for sample inputs and waste output, thermal grooves, and valve seats for flow control on the bottom side. The coverplates and substrates were fabricated with double-sided hot embossing of polycarbonate (PC) using four micromilled brass molds, two for the coverplate and another two for the substrate. Evaluation of the relative front-to-backside alignment for the double-sided hot embossing yielded an accuracy of 25 μm ± 14 μm (average ± standard deviation) for the coverplates and 30 μm ± 20 μm for the substrates. Thermal fusion bonding (TFB) of the coverplate and substrate was done using a spring plunger bonding setup with a range of temperatures and pressures. The motherboard bonded at 154 °C and 12.0 psi for 2 hours in a convection oven produced complete bonding with a little deformation of the valve seats. The complete motherboard will be integrated with the task-specific processing modules in the uMPS for investigating circulating markers from whole blood for precision molecular diagnosis of disease at low cost and with high fidelity.