Self-anchoring nickel microelectrodes for rapid fabrication of functional thermoplastic microfluidic prototypes

• A new method for fabricating integrated microelectrodes in plastic microfluidic devices has been developed.
• A reliable and repeatable method provides the means to combine different materials in one platform.
• The embedded microelectrodes provide complete functionality to microfluidic devices.
• Point-of-care devices or lab on a chip could be benefit from this new way of manufacture.
• It is possible to use this technology to integrate silicon-based sensors into microfluidic devices.
• We shrink the gap between research and commercialization of microfluidic devices.

Microfluidic devices play an increasingly important role in healthcare-related fields, but integration of electrodes and electronic components has been restricted at the prototyping stage of product development by a limited range of fabrication methods. In this work a new fabrication methodology is presented for embedding metallic microelectrodes in thermoplastic microfluidic devices. Microelectrodes are fabricated on steel wafers by means of photolithographic patterning and electrodeposition and then transferred to a thermoplastic sheet using hot embossing, resulting in embedded metal electrodes flush with the polymer surface. The unique shape of the microelectrodes provides an anchoring mechanism that ensures structural stability and reliability of the devices. A wide variety of thermoplastics can be used in this process including polycarbonate, polymethylmethacrylate (PMMA), and cyclic olefin copolymer (COC). Devices are assembled by a solvent-assisted bonding process, after drilling the inlets and outlets. This method allows for rapid fabrication of robust embedded electrodes and wiring connections from a broad range of metals for thermoplastic microfluidic devices. Finally, embedded interdigitated microelectrodes are used to measure conductivity within a microchannel via impedance spectroscopy analysis. The use of this technology is relevant to a wide range of analytical applications.

Novel approach for the fabrication of whole plastic microfluidic devices with embedded metallic electrodes using a robust self-anchoring approach (like a mushroom shape cross section). This unique shape of the microelectrodes provides an anchoring mechanism that ensures structural stability and reliability of the devices.Figure optionsDownload as PowerPoint slide