Low temperature co-fired ceramics for micro-fluidics

The miniaturization of analytical instruments and packaging of novel sensors is an area that has attracted significant research interest and offers many opportunities for product commercialization. Low temperature co-fired ceramics (LTCC) is a materials system composed of alumina and glass in an organic binder. LTCC is a good choice for sensor development because of the ease of incorporating features in the 'green' or unfired state such as electrical traces, fluidic pathways and passive electrical components. After a firing cycle, what remains is a robust, monolithic device with features embedded in the package. In order for LTCC to be a successful medium for small scale sensors or lab-in-package devices, fluid flow through channels and inlet/outlet ports must be perfected. Device inlet/outlet ports have been demonstrated by embedding sapphire tubes in LTCC, allowing external connections using compression fittings. Channels and cavities have been fabricated through the use of sacrificial carbon tapes and pastes. A field flow fractionation device used for separating or concentrating constituent components in a fluid and a multi-electrode electrochemical cell were fabricated with the techniques described in this paper.