Utilizing Cutting-Edge Digital Light Processing for 3D Printing Microfluidic Chips

Traditional manufacturing methods like soft lithography and hot embossing can be employed for bioengineering microfluidic chips. However, these methods have limitations including difficulties in creating multilayered structures, costly and labor-intensive fabrication processes, and low productivity.

To address these challenges, materials scientists have introduced digital light processing (DLP) as a cost-effective microfabrication approach for 3D printing microfluidic chips. However, the resolution of microchannels produced using DLP is limited to sub-100 microns.

In a recent report published in Microsystems and Nanoengineering, a team of scientists led by Zhuming Luo from biomedical and chemical engineering departments in China developed an innovative DLP method. They proposed a modified mathematical model to predict UV irradiance for resin photopolymerization, which guided the fabrication of microchannels with increased resolution. This advanced microfabrication method has the potential to drive significant advancements in precise and scalable microchannel formation, a critical step for expanding the applications of microfluidics in biomedicine.

Microfluidic chips are powerful tools for miniaturizing 3D cell culture, drug screening, organ-on-a-chip assays, and more. Conventional methods for developing these chips, such as soft lithography and hot capillary fabrication, are cumbersome, low-yield, and expensive.

In contrast, 3D bioprinting using DLP enables layer-by-layer vat photopolymerization with resolutions in the tens of microns range, offering rapid processing and ease of use. In their work, Luo and colleagues developed a novel DLP method for high-resolution and scalable fabrication of microfluidic devices through dosing- and zoning-regulated vat photopolymerization (DZC-VPP). They fine-tuned printing parameters to precisely control resin layer polymerization, preventing channel blockage due to excessive UV exposure.

Compared to conventional methods, this process allowed the simultaneous creation of up to 16 microfluidic chips in a single batch. This method represents a significant advancement in precise and scalable microchannel development, particularly for biomedicine applications.

To regulate UV irradiation, the team employed a stepwise UV polymerization approach guided by their mathematical model. This allowed for the precise division of the microchannel into bottom, channel, and roof layers, resulting in microchannels with significantly higher resolution.

In terms of mechanical stability, the DZC-VPP fabricated chips exhibited superior fracture stress and strain compared to chips produced using conventional DLP printing. This improvement in printing resolution and mechanical stability enhances the reliability of these engineered microfluidic chips.

The researchers also demonstrated the utility of their DZC-VPP method for generating droplets and microgels and encapsulating cells within microgels. Both HeLa cells and rat mesenchymal cells retained viability and proliferated within the microgels, indicating the biofriendly nature of the DZC-VPP engineered microfluidic device. This method is well-suited for various cell-related applications, including organ-on-a-chip development.

In summary, Zhuming Luo and his research team have pioneered a DZC-VPP method for 3D printing microchannels with improved resolution and mechanical stability. Their approach, guided by a mathematical model, enables the high-resolution fabrication of microfluidic devices, offering significant potential for widespread applications in biomedicine.

Leave a Comment