Development of laser fabrication methods for lab-on-a-chip microfluidic multisensing devices in the past decades

Abstract

Microfluidics is a specialized field that focuses on manipulating and controlling small volumes of fluids, enabling rapid analysis and integration of multiple analytical operations into a single device known as a lab on a chip (LOC). Working with small volumes brings several benefits, including improved safety, environmental protection, cost savings, and handling of limited samples. This chapter discusses the fabrication technologies for microfluidic devices, with a focus on advancements in laser fabrication techniques. Initially, microfluidic devices were fabricated using silicon and glass materials, but there has been a surge in the use of polymeric materials due to their diverse properties. Polydimethylsiloxane (PDMS) remains widely used, while thermoplastic polymers like PMMA and PC offer cost-effective options. Cyclic olefin polymers (COPs) and cyclic olefin copolymers (COCs) have gained popularity due to their chemical resistance and optical transparency. The impact of different materials on analytical performance is evaluated. Paper has also emerged as a low-cost material for microfluidic devices. Standard fabrication methods include photolithography, etching, soft lithography, precision micromachining, hot embossing, injection molding, and laser ablation. Photolithography and etching are commonly used for silicon and glass substrates, while laser ablation and other techniques are suitable for polymers. The abstract provides an overview of the materials employed in microfluidic device fabrication and the standard fabrication methods used in the field.