Abstract

Microfluidics is a multidisciplinary area comprising several disciplines such as biology, chemistry and tissue engineering, which leads to manipulation and analysis of liquid through micro channels. Microfluidic devices provide numerous advantages for economical point-of-care diagnosis compared to conventional testing devices. In addition, more recently organ-on-a-chip which is a 3D microfluidic network for cell culturing has offered a microfluidic chip that stimulates the response of an organ system which can significantly reduce the costs of developing new pharmaceutical drugs. In spite of multiple advantages of microfluidic devices, barriers exist in current microfabrication methods. Fabrication of microfluidic molds requires cleanroom facilities and is a costly and tedious process which hindered the commercialization of microfluidic chips. Although, using 3D printed molds has been suggested to simplify fabrication of chips, their resolution is limited to 100 μm. In addition to these factors, molding process is challenging to fully automate which means that it is in contrast to the vision of cost-effective and mass production of these devices. Therefore, a fully automated, rapid process is required to guide microfluidics towards the development of low-cost more commercially devices.
In this thesis, different additive manufacturing methods for fabrication of polymeric microfluidic devices are presented. First, a commercial stereolithography (SLA) 3D printer was used to fabricate 3D printed molds. Limitations and accuracy of using 3D printed templates for microfluidic applications were investigated. Then, the thesis presents a promising additive manufacturing method toward printing a polymer-based device by using an acoustic assisted printing method. This method can significantly simplify and improve fabrication of microfluidic devices. Simulation of the acoustic wave and the heat induced by that were obtained in order to optimize the printing process prior to the experiment. The model provided a good understanding and estimation of acoustic field, temperature rise and focal region size. Time and cost required for fabricating a part by this method is considerably low and no additional post processing is required to turn the printed part to a functional part. The proposed method was finally applied to fabricate a fluidic channel. A fluidic channel can be printed in less than 10 minutes without adding additional components.