Fabrication of microfluidic chips with varying geometries using soft lithography and adjustable moulds

Microfluidic devices have been used for a wide range of applications including drug development and lab-on-a-chip devices. Soft lithography, commonly used to fabricate submillimetric channels, utilizes moulds to fabricate polydimethylsiloxane (PDMS) channels. Biocompatible, gas permeable and transparent PDMS is ideal for microfluidic applications. Mould Fabrication is the most expensive and time-consuming part of the soft lithography process. Formerly proposed research methods aimed to decrease cost and increase manufacturing times included 3D printing, micromolding, and micromachining. These approaches, however, exclusively provide specific channel geometry per mould design. A novel technique is proposed in this project to fabricate channels of varying geometries using an adjustable mould. Slotted and retractable pieces demonstrate the feasibility of this approach, providing the fabrication of adjustable moulds and, consequently, varying microfluidic channel geometries. Moreover, the curing time and temperature for facilitating the best lift-off properties were optimized. Finally, the duration and intensity of corona treatment were optimized for leakproof bonding of PDMS to glass. Future steps intend to minimize channel size within the adjustable microfluidic chip and applying these concepts to the encapsulation and growth of bacteria deemed typically unculturable and novel. Simultaneously, this project reduces the cost and development factors within the fabrication of microfluidic chips