Analysis and Fabrication of Microfluidic Systems by Excimer Laser Micromachining and Its Applications for Microfluidic and Bio-Medical Devices

This study primary focuses on identifying the relationship between laser micromachining parameters and the functionality of micro bio-device design. Micro biodevices such as Lab-on-a-chip (LOC) and microarrays are an emerging technology that recently attracts a lot of attention. For successful applications in the area, the fabrication methods and the system functionality should be addressed. Excimer laser machining is a good candidate to apply to the micro bio-devices manufacturing because different materials can be machined and the process can be easily controlled compared to other fabrication methods.;In the thesis, a parametric study of laser micro machining on different materials are conducted: efforts were focused on identifying the relationship between the laser micromachining parameters and micro bio-device functionality. Experimental study and analytical modeling for the parametric study of excimer laser machining were performed to analyze the machined surface quality and the material removal rate of polyethylene, PMMA and silicon. Microfluidic experiments were carried out to verify liquid flow on laser machined microchannels.;In this study, a novel geometrical model is presented to calculate a contact angle of liquid on the solid substrate to apply for micro bio-device manufacturing. The contact angle can be used to optimize designs of microarrays and microfluidic devices on development state. Based on a simplified geometry of a droplet, the wetting distance was derived as the function of liquid volume, a contact angle and material properties. To verify our method, the contact angles of a few materials were measured with goniometer, and the results were compared with the contact angle identified by our model. This method can be simplified the current method and the result can be used for design estimation of micro bio-device.;Examples of the proposed technique were presented in the fabrication of inkwells for Dip-Pen Nanolithography (DPN) applications. This study verified that the channel fabricated by laser micromachining allows well-developed liquid flow through the microchannels. The presented methods can be used for laser micro/nano machining of micro bio-devices development and biomedical application.