Rising Millifluidics: A Practical Approach Towards Wide Application

This study provides a comprehensive review of millifluidic devices, the devices that handle liquids on the millimeter scale. Millifluidics is being developed as an extension of microfluidic technology. Millifluidic devices share a similar design, fabrication, and characterization approach compared to microfluidics; however, millifluidic devices have the advantages of low cost, high throughput, and visible fluid flow, and are much more accessible to researchers in various fields. The application fields of millifluidics are also similar to those of microfluidics, for example, chemical/bio reactions, micro/nanoparticle synthesis, droplet generation, and detection. According to recent developments in microfluidics and millifluidics, in certain fields, millifluidics tends to partially replace microfluidics, e.g., particle synthesis. In addition, more fluidics handling devices (e.g., test cartridges) have combined features of fluid manipulation structures in the micrometer and millimeter ranges. Artificial intelligence and machine learning have also been used for the design and control of millifluidic devices. This study provides a new insight into the conventional application field of microfluidics, which could be a low-cost, more accessible, high-throughput solution to real-world tasks in the chemical, biomedical, and environmental fields.