C. Millot

Investigation on Replication of Microstructures on Flexible Substrates by Roll Embossing Process

The roll embossing is an efficient process to replicate micro‐patterns at continuous polymeric films. This process has been selected for its capabilities for manufacturing by rapid fabrication concepts high quality micro‐structures on polymeric thin films. The aim of this work is to develop experimental investigations and analyses of the proper embossing conditions (embossing velocity; material pressure and temperature) needed for the replication of micro‐structured parts with various geometries and sizes. In the present analysis, one propose a comparative that investigation considering filling rate, roughness and shape of embossed structures that have been realised and examined. The paper demonstrates that roll embossing shows proper replication facilities at the micro‐scale, to reproduce same geometrical dimensions and surface roughness than these corresponding to the cavities.

Modelling and experimental determination of the replication of a cylindrical shape relief

In that paper, one uses the concepts of contact mechanics to describe the quality of reproduction of cylindrical cavity shape by hot embossing. It results in a negative replica of the initial shape. This model takes into account the deformation of the polymer material imposed by the forming process. These results point out the influence of experimental parameters (temperature, pressure) as well as those of the elastic modulus (Young’s modulus and Poisson’s ratio). The analytical data are compared with the metrology results obtained using a scanning mechanical microscope in two or three‐dimensional mode. The set of data enables a predictive approach of the engraving quality depending on the polymer mechanical properties. The final goal is to adapt this model to the hot embossing process.

On the use of hot embossing for the reproduction of the surface topography of mould microreliefs

Abstract This article describes the quality of reproduction of microcavities structured into mould substrates which were filled by the imposed flow of amorphous polymeric materials. The rheology of the selected materials (cyclic olefin copolymer, COC) depends on the experimental parameters (temperature, pressure) used for the hot embossing process. To support the experimental data, the polymers were qualified by their melt flow index, flow index and consistency. The efficiency of the filling procedure into microcavities with smaller and smaller size is described using the potentialities of a customized Scanning Mechanical Microscope (SMM).