Assembly of a polymer lab-on-chip device for impedimetric measurements of D-dimers in whole blood

This paper reports the development and characterisation of an assembly technology for a polymer lab-on-chip. The system consists of a 150 μm deep hot embossed microfluidic channel in polycarbonate and Au electrodes fabricated separately by photolithography on polyethylenenaphthalate. The system is designed for impedimetric immunoassay detection in whole blood. Electrode layer and microfluidic substrate are joined by means of a 50 μm thick double-sided medical grade adhesive tape, adjusted with an optical alignment system. The bond proved to be liquid tight at room temperature. An alignment accuracy of 34 μm (+/- 19 μm) evaluated over a set of 23 samples, was achieved. The effect of alignment accuracy of the intermediate adhesive film on whole blood flow properties in the device is studied. Already an alignment error of 70 μm increases the flushing out time of whole blood by approximately 20%.