Multilayered microreactor system

Fig. 32 Flow microreactor system consisting of a polydimethylsiloxane (PDMS) multilayered laminar micromixer and PTFE microtubes for polymerization of amino acid A-carboxyanhydride (NCA) initiated by triethylamine...

Small PEMFC system with multilayered microreactor. In Proceedings of PowerMEMS, Kyoto, 28-30 November 2004, pp. 142-145. 

For enzyme attachment to the silicon microreactor tested, a layer-by-layer technique was employed to build a multilayer system of polyions and enzyme. Deposition of multilayers was accomplished by alternating positively and negatively charged layers of polydimethyldiallyl ammonium chloride (PDDA) and polystyrene sulfonate (PSS), respectively, to which was attached urease enzyme. After depositing in succession three layers of PDDA, PSS, and PDDA, three layers of urease enzyme were alternately deposited with three layers of PDDA. The resulting architecture is described as follows ... 

Studies on PEM are of interest because of the versatility of multilayer formation process with respect to variety of support materials, combination with other assembly techniques and possibility of incorporation of different functional species [1-4]. PEM are applied in chemical and biochemical sensing or preparation of new biomaterials. When colloidal particles or emulsion droplets are used as cores for polyelectrolyte deposition one can obtain hollow micro- and nanocapsules. Such capsules have potential as drug delivery systems [5] capable of sustained release [6,7], microreactors [8,9] or catalytic systems [8-10]. Detailed summaries on the properties and application of PEM prepared by LbL technique can be found in [1,11]. 

If multilayer systems are to be manufactured, suitable bonding methods are needed. Attention must be paid not only to the mechanical stability of the bond but also to its resistance to chemicals and changes of temperature. Bonding by means of modern glues is not impossible but is rarely used in the construction of microreactors. The prerequisite for tension-free bonding is similar coefficients of linear thermal expansion. The following bonding processes are of importance ... 

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