Electrostatic bonding of a silicon master to a glass wafer for plastic microchannel fabrication

Fabrication of microchannels on polymethylmethacrylate (PMMA) substrates using novel microfabrication methods is demonstrated. The image of microchannels is transferred from a silicon master possessing the inverse image of the microchannel to a PMMA plate by using hot embossing methods. The silicon master is electrostatically bonded to a Pyrex7740 glass wafer, which improves the device yield from ∼20 devices to hundreds of devices per master. Effects of embossing temperature, pressure and time on the accuracy of replication are systematically studied. According to the suggested experimental model, the time for the whole embossing procedure is shortened from about 20 to 6 min, and the accuracy of replication is 99.3%. The reproducibility of the hot embossing method is evaluated using 10 channels on different microfluidic devices, with variations of 1.4% in depth and 1.8% in width.