Microfluidics on foil: State of the art and new developments

Abstract

The concept of microfluidics on foil opens up new opportunities for combining the advantages of having a flexible substrate with reel-to-reel processing, which has the potential to be the basis for extremely cheap micro products. To reach this goal, foil substrates must be combined with micro-manufacturing technologies that are well adapted to these substrates. Some technologies are already available, some are the subject of current research, and some still have to be conceived. In the current paper, technologies such as reel-to-reel embossing, reel-to-reel laminating, and laser ablation/cutting as well as laser welding will be discussed. The discussions include a brief review of the state of the art as well as a report on latest research results stemming from research by the present authors. Furthermore, this paper shows the vision of what can be achieved if foil-based technologies, such as polymer (opto-) electronics and microfluidics are combined. A polymer electronics-based alcohol sensor is presented as an example system

Rapid polymer microchannel fabrication by hot roller embossing process

“…Instead of using a UV light source, hot roller embossing uses a hot roller to heat the thermoplastic film above its T g , imprints the microstructure onto the thermoplastic film, and releases the imprinted film from the mold. Several types of thermoplastic materials, including poly(methyl methacrylate) (PMMA) Yeo et al 2010), PET (Ishizawa et al 2008), PVC (Shan et al 2010), polystyrene (PS) (Seo et al 2007), and PC (Velten et al 2008) have been used in the hot roller embossing process.…”

Roll manufacturing of flexible microfluidic devices in thin PMMA and COC foils by embossing and lamination

“…However, polymer foils can offer a lot of advantages like transparency variation, biological compatibility, full flexibility and robustness. The techniques of interest for the manufacture of polymer-foil based microfluidic devices (Focke et al 2010) are those allowing the production of a large number of devices using for example photolithographic methods (Tsai et al 2006;Khan-Malek and Robert 2008), lamination (Abgrall et al 2008;Khan-Malek et al 2009), or using replication techniques, where a master structure is replicated into the polymer material by techniques such as thermoforming (Focke et al 2009) or embossing (Paul et al 2007;Velten et al 2008). Each of these manufacturing methods has its applicability, flexibility, up-scalability, robustness, and cost-efficiency.…”

“…Each of these manufacturing methods has its applicability, flexibility, up-scalability, robustness, and cost-efficiency. In particular, continuous processing of flexible devices using thin films can be carried via roll-to-roll manufacturing (Velten et al 2008). Roll embossing where rollers are used instead of the plates of planar embossing, is emerging as a viable fabrication technology which provides advantages such as reduced cycle time and large processing area.…”

Roll-to-roll large-format slot die coating of photosensitive resin for UV embossing

“…There is much ongoing research to develop roll-to-roll embossing and increase its range of applications Guo 2008, 2009;Kololuoma et al 2004;Krebs 2009;Mäkelä et al 2007;Nagato et al 2010;Velten et al 2008;Yeo et al 2010). By fulfilling the aims of lower cost and higher throughput, roll-to-roll embossing is targeted to be a commercially viable method for fabricating of micro and nano scale structures.…”