Abstract
This report describes the fabrication of micro-fluidic device using double-stage hot embossing for application in clinical examinations. The material chosen as the master mold for the polytetrafluoroethylene (PTFE) substrate in fabrication of microchannels by double-stage hot embossing is very important. Polycarbonate (PC), polyetherimide (PEI), and polyamide-imide (PAI) were selected as materials for the middle polymer mold to fabricate microchannels and examined the effects of embossing temperature, embossing pressure, and holding time. We established the relationship between hot embossing conditions and replication accuracy of embossed microchannels to choose the optimal middle polymer. The results showed that PEI is the optimal material for double-stage hot embossing. The optimal process parameters in the first-stage hot embossing were: embossing temperature, 235°C; embossing pressure, 14.7 MPa; holding time, and 1 minute. The optimal process parameters in the second stage were: embossing temperature, at 190°C; embossing pressure, 11.3 MPa; holding time, 1 minute. Using the optimal process parameters of PEI, the replication accuracies of microchannels on the PTFE substrate reached about 95% ∼ 105%. Consequently, it was verified that double-stage hot embossing has the same capability as hot embossing, which is applied for the fabrication of microchannels on PTFE substrates
