Film transfer and bonding technique to cover lab on a chip

This paper describes a novel film transfer technique with a new bonding technique to cover microfluidic components, (on a silicon chip) with a 6 μm thick parylene layer. We have developed a batch-process technique for covering microfluidic systems such as a lab on a chip with a thin film, and applied it to packaging an integrated microfluidic system containing a liquid-droplet ejector array, microchannels and reservoirs on a chip. The well-attached cover without any leaks makes it possible for capillary force to bring liquid into the ejectors from the reservoirs through microchannels, so that the ejectors are supplied with the liquid(s) automatically from the reservoirs. The new bonding technique reported in this paper accomplishes a bonding at room temperature by using capillary flow and surface tension of low viscous aqueous bonding materials without any added pressure, and can also bond many different materials at a very low processing cost.