Bonding process using integrated electrothermal actuators for microfluidic circuit fabrication

In this paper, the fabrication of plastic microfluidic circuits using integrated electrothermal actuators is described. The materials used to do this task are aluminium, biocompatible glue and polymethylmethacrylate (PMMA). These materials are processed to integrate electrothermal actuators on transparent and biocompatible PCB-like substrates. The actuators reach a temperature between the glass transition temperature and the melting point of the PMMA in order to perform the bonding. The PCB-like substrate allows the integration of additional circuitry if required. The proposed method of fabrication guarantees transparent devices. To do this task, the facilities are not expensive, and allow industrial production because many devices can be assembled at the same time. Finally, the proposed method is checked. In order to do so, a T-junction microfluidic circuit for bubbles generation is fabricated. The microchannels have a width of 600 mu m and a height of 1300 mu m. The generation of bubbles was tested with successful results and good correspondence with the theoretical behaviour. Leakages were not observed during experiments, demonstrating the feasibility of the bonding method for fabricating microfluidic devices using thermoplastics materials.