Development of a multi-layer microelectrofluidic platform

Abstract

We report on the development of process capabilities for a polymer-based, multi-layer microelectrofluidic platform, namely: the hot embossing process, metallization on polymer and polymer bonding. Hot embossing experiments were conducted to look at the effects of load applied, embossing temperature and embossing time on the fidelity of line arrays representing micro channels. The results revealed that the embossing temperature was a more sensitive parameter than the others due to its large effect on the polymer material's viscoelastic properties. Dynamic mechanical analysis (DMA) conducted on polymethyl methacrylate (PMMA) revealed a steep glass transition over a 20°C range, with the material losing more than 95% of its storage modulus. The data explained the hot embossing results, which showed large changes in the embossed channel dimensions when the temperature was within the glass transition range. It was demonstrated that the micro-printing of silver epoxy was a possible low-cost technique in the mass production of disposable lab chips. An interconnecting, three-dimensional network of electrical traces was fabricated, as well as a microfluidic device with interconnecting, three-dimensional network of micro channels.

Hot roller embossing for microfluidics: process and challenges

“…The process is different from hot embossing where the polymer substrate is given ample time to heat up and cooling is carried out with the force still applied. Table 1 lists some differences between the conventional hot embossing (Ng et al 2007) that uses a flat, rigid mould and hot roller embossing. Typically, conventional hot embossing can give a better replication of the mould because the polymer can be demoulded at a temperature below its glass transition temperature, minimizing any polymer flow after the mould is removed.…”

Roll manufacturing of polymer microfluidic devices using a roll embossing process

“…As shown in Fig. 16, the mould cavities could be fully filled and the grating structure is well-defined after embossing at 260 • C [34]. The temperature is one of the most important parameters in the roll embossing process.…”

“…22 shows some of the samples after roll embossing. When the COC substrate was heated to above its T g of 120 • C [34] and with adequate embossing pressure and time, the elastomeric mould features were transferred.…”

Hot roller embossing for the creation of microfluidic devices

“…The process is different from hot embossing where the polymer substrate is given ample time to heat up and cooling is carried out with the force still applied. Table 1 lists some differences between the conventional hot embossing [5] that uses a flat, rigid mould and hot roller embossing. Typically, conventional hot embossing can give a better replication of the mould because the polymer can be demoulded at a temperature below its glass transition temperature, minimizing any polymer flow after the mould is removed.…”