Process parameter effects on dimensional accuracy of a hot embossing process for polymer-based micro-fluidic device manufacturing

The embossing of polymeric materials is widely used for manufacturing of micro-parts. The thermoplastic amorphous polymers are always selected to get micro-components. The paper consists to characterise the thermal mechanical properties of three amorphous polymers: polystyrene (PS), poly(methyl methacrylate) (PMMA) and polycarbonate (PC). A set of experiments such as differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) have been carried out with PS, PMMA and PC. The thermoplastic polymers' behaviours have been characterised above their glass transition temperature. Then, flexible microfluidic devices have been manufactured with the polymers by hot embossing process. The surface topography of mould die cavity insert and the micro-fluidic devices have been observed and analysed by a 3D optical microscopy viewing and measurement system in order to compare the replication accuracy for polymeric replicas. The surface roughness of the microfluidic devices has been measured to characterise the effect of the compression load and temperature in the hot embossing process. The paper is mainly concentrated on the effect of the process parameters with different amorphous thermoplastic polymers to achieve the process optimization. The results concerning the micro-and nano-scale cavities filling provide information on the reliability about the facilities to replicate complex surface topographies. In this paper, the flow behaviour of polymer during forming process thus process parameters would be investigated. The mould instrumented with micro-structured patterns will be presented. The relationship between embossing conditions and parts quality will be established.