A miniaturised integrated QCM-based electronic nose microsystem

We designed, fabricated and successfully tested an integrated miniaturised quartz crystal microbalance (QCM) based electronic nose microsystem. The microsystem is an assembly of four parts: 1. a micromachined gas-liquid interface with integrated fluid channels and electrical conductors, 2. an anisotropically conductive double-sided adhesive film, 3. a QCM crystal and 4. a polymer cap with fluid and electrical ports. The choice of the multifunctional materials and the geometric features of the four-component microsystem allow a functional integration of a QCM crystal, electrical contacts, fluidic contacts and a sample interface in a single system with minimal assembly effort, a potential for low-cost manufacturing, and a few orders of magnitude reduction in system size (12* 12*4 mm3) and weight compared to commercially available instruments. The system detected ecstasy in the 100 ng range within 30 seconds.