Research on Integrated 3D Printing of Microfluidic Chips

Automated Dynamic Inlet Microfluidics (ADIM) system: cost-effective biaxial nanoliter droplet on demand generation platform and its application in agglutination assays

The paper demonstrates an adaptation of a Prusa Mini+ 3D printer through the integration of 3D printed modules, creating a system capable of producing varied droplets from multiple Eppendorf tubes. Building upon our previous model, this system enhances calibration methodology enabling any fused deposition modeling (FDM) printer to produce mono-disperse droplets (coefficient of variance (CV%) <2% for train of 100 droplets) with 6900 assays per hour rate. The cost of the developed system is 85% lower than that of existing droplet generation solutions on the market, and 30% more economical than the previous iteration of the system. Additionally, the system's utility in quantification of agglutination assays is highlighted using image analysis, capable of distinguishing between agglutinated and non-agglutinated samples. By offering significant savings and ease of use, this system aims to lower the barriers to entry for microfluidic research, potentially broadening the scope of scientific exploration and application in this field.

A Thorough Review of Emerging Technologies in Micro- and Nanochannel Fabrication: Limitations, Applications, and Comparison

In recent years, the field of micro- and nanochannel fabrication has seen significant advancements driven by the need for precision in biomedical, environmental, and industrial applications. This review provides a comprehensive analysis of emerging fabrication technologies, including photolithography, soft lithography, 3D printing, electron-beam lithography (EBL), wet/dry etching, injection molding, focused ion beam (FIB) milling, laser micromachining, and micro-milling. Each of these methods offers unique advantages in terms of scalability, precision, and cost-effectiveness, enabling the creation of highly customized micro- and nanochannel structures. Challenges related to scalability, resolution, and the high cost of traditional techniques are addressed through innovations such as deep reactive ion etching (DRIE) and multipass micro-milling. This paper also explores the application potential of these technologies in areas such as lab-on-a-chip devices, biomedical diagnostics, and energy-efficient cooling systems. With continued research and technological refinement, these methods are poised to significantly impact the future of microfluidic and nanofluidic systems.

Automated dynamic inlet microfluidics system: 3D printer adaptation for cost-effective, low volume, on-demand multi-analyte droplet generator

The paper demonstrates an adaptation of a 3D printer (Prusa Mini+) with novel modules to develop a droplet generation system that generates combinatorial droplets from a standard 96 well plate. The calibration methodology developed would allow any fused deposition modeling (FDM) printer to generate monodisperse droplets (coefficient of variance (CV%) < 5%) from well plates or vials of any geometry. The system maintains precision across various volumes while maintaining a C.V. range of 0.81% to 3.61%, with an increased precision for larger volumes. The cost of the system developed is 70% less than commercially available droplet generation packages. Successful droplet library storage is accomplished via 3D printed cartridge connectors. The implemented system has been calibrated for Tygon® and PTFE at different velocities and volumetric configurations.

Advances in Microfluidics Techniques for Rapid Detection of Pesticide Residues in Food

Food safety is a significant issue that affects people worldwide and is tied to their lives and health. The issue of pesticide residues in food is just one of many issues related to food safety, which leave residues in crops and are transferred through the food chain to human consumption. Foods contaminated with pesticide residues pose a serious risk to human health, including carcinogenicity, neurotoxicity, and endocrine disruption. Although traditional methods, including gas chromatography, high-performance liquid chromatography, chromatography, and mass spectrometry, can be used to achieve a quantitative analysis of pesticide residues, the disadvantages of these techniques, such as being time-consuming and costly and requiring specialist staff, limit their application. Therefore, there is a need to develop rapid, effective, and sensitive equipment for the quantitative analysis of pesticide residues in food. Microfluidics is rapidly emerging in a number of fields due to its outstanding strengths. This paper summarizes the application of microfluidic techniques to pyrethroid, carbamate, organochlorine, and organophosphate pesticides, as well as to commercial products. Meanwhile, the study also outlines the development of microfluidics in combination with 3D printing technology and nanomaterials for detecting pesticide residues in food.

Hemagglutination Assay via Optical Density Characterization in 3D Microtrap Chips

Hemagglutination assay has been used for blood typing and detecting viruses, thus applicable for the diagnosis of infectious diseases, including COVID-19. Therefore, the development of microfluidic devices for fast detection of hemagglutination is on-demand for point-of-care diagnosis. Here, we present a way to detect hemagglutination in 3D microfluidic devices via optical absorbance (optical density, OD) characterization. 3D printing is a powerful way to build microfluidic structures for diagnostic devices. However, mixing liquid in microfluidic chips is difficult due to laminar flow, which hampers practical applications such as antigen-antibody mixing. To overcome the issue, we fabricated 3D microfluidic chips with embedded microchannel and microwell structures to induce hemagglutination between red blood cells (RBCs) and antibodies. We named it a 3D microtrap chip. We also established an automated measurement system which is an integral part of diagnostic devices. To do this, we developed a novel way to identify RBC agglutination and non-agglutination via the OD difference. By adapting a 3D-printed aperture to the microtrap chip, we obtained a pure absorbance signal from the microchannels by eliminating the background brightness of the microtrap chip. By investigating the underlying optical physics, we provide a 3D device platform for detecting hemagglutination.