Encapsulation of integrated circuits in plastic microfluidic systems using hot embossing

A method for fabricating thermoplastic cartridges encapsulating integrated circuits, electrodes, and microfluidic channels using hot embossing is described for the application of a point of care magnetic label flow cytometer. Finished devices with a microchannel depth of 86 μm and RMS surface roughness of 1.6 μm are capable of operating at pressures of up to 227 kPa without leaks. The device was used to evaluate the efficiency of an on chip magnetic focusing structure which successfully focused 98% of the 4.5 μm Dynabeads® to a 30 μm target region using 100 mA of current and a 4 mT external field.