Precision Engineering at Micro and Nano Scales: Harnessing Laser Technologies for Fluidic Systems

In the last decade, the research and development of micro and nanofluidics have made extraordinary progress in revolutionizing lab-on-a-chip systems for the biological and chemical industries. Thanks to the properties of microfluidic technologies, such as rapid sample processing and the precise control of fluids with much improved detection limits, these systems can improve on traditional experimental approaches by providing faster and more accurate biological and chemical analysis, and thereby improved diagnosis n the 1990s, governments began explor-ing the possibility of incorporating microfluidic chips into a portable and miniaturized laboratory known as a lab-on-a-chip (LOC) as an alternative to the model of centralized laboratories processing clinical samples with expensive equipment. LOCs can provide low cost point-of-care (POC) diagnostics as exemplified by the recent development of desktop polymerase chain reaction (PCR) and at home rapid antigen tests for Covid-19. According to Precedence Research, the global microfluidics market is pro-jected to increase from 18 billion US dollars in 2021 to around 62 billion by 2030, at a CAGR of 16.5% . The main market drivers are increased demand for POC devices, low volume sample analysis ysis, and in-vitro diagnostics as well as high-throughput screening methodologies and the development of advanced lab-on-a-chip technologies.

Microfluidics fabrication

Major lab-on-a-chip research began in the late 80s with the development of microfluidics, which comprises channels of nanometer dimensions typically smaller than several hundred nm, and microfabrication processes to produce polymer chips called soft-lithography. In the 1990s, soft lithography, a technique involving the replication of various structures by using elastomeric stamps or molds, was superseded by various types of lithography such as electron beam lithography (EBL) and nanoimprint lithography that could create patterned structures of nanoscale feature sizes, with high accuracy and flexibility in replication, to a processing resolution below 10nm. However, these techniques have several drawbacks, including their cost, fouling and clogging of the microchannels, difficulties in creating graded or hierarchal configurations and providing nanochannel connectivity. As a way of overcoming these issues, ultrafast laser manufacturing has emerged in the last decade as a promising alternative for the fabrication of nanofluidics due to its flexibility, versatility, high fabrication resolution and 3D fabrication capability.