  We report on the development of some 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 is a more
sensitive parameter than the others due to its large effect on the polymer
material's viscoelastic properties. Dynamic mechanical analysis (DMA) on
polymethyl methacrylate (PMMA) revealed a steep glass transition over a 20 oC
range, with the material losing more than 95 % of its storage modulus. The data
explained the hot embossing results which showed large change in the embossed
channel dimensions when the temperature is within the glass transition range.
It was demonstrated that the micro-printing of silver epoxy is a possible
low-cost technique in the mass production of disposable lab chips. An
interconnecting network of electrical traces was fabricated in the form of a
four-layer PMMA-based device. A four PMMA layer device with interconnecting
microfluidic channels was also fabricated and tested.
