New rapid prototyping method for microscale spiral devices

A team of researchers from Tohoku University and the Okinawa Institute of Science and Technology (OIST) has made significant progress in the field of microfluidics, enabling precise and efficient manipulation of fluids in three-dimensional microscale environments . This work opens up new possibilities for bioanalytical applications, such as cell separation in the field of medical diagnostics.

Details of their breakthrough were published in the journal Microsystems and nanoengineeringon January 22, 2024.

Microfluidic devices are designed to handle tiny fluid volumes, allowing researchers to perform analyzes and processes with remarkable precision and efficiency.

In recent years, microfluidic technology has advanced rapidly in various fields, including medicine, biology, and chemistry. Among them, three-dimensional spiral microfluidic devices stand out as revolutionary elements. Their complex corkscrew design allows for precise fluid control, efficient particle separation and reagent mixing. However, their potential to revolutionize bioanalytical applications is hampered by current manufacturing challenges. The process is time-consuming and expensive, and existing manufacturing techniques limit material options and structural configurations.

To overcome these limitations, an interdisciplinary team from Tohoku University and OIST introduced a miniaturized rotary thermal drawing process (mini-rTDP), drawing inspiration from traditional Japanese candy making techniques: candy making. Kintaro-ame.

Their innovative approach involves rotating materials during thermal stretching to create complex three-dimensional structures within the fibers. This process is very versatile and accommodates a wide range of materials that can warp when heated, opening up endless possibilities for combining various materials.

“The mini-rTDP facilitates rapid prototyping of three-dimensional microfluidic systems, ideal for precise manipulation of biofluids,” says Yuanyuan Guo, associate professor at the Frontier Research Institute for Interdisciplinary Sciences (FRIS) at Tohoku University.

“Mini-rTDP involves creating a molded polymer preform containing channels, which are then stretched and heated to generate microfluidic channels within a fiber. These channels can then be further rotated to shape three-dimensional spiral configurations,” explains Shunsuke Kato, junior researcher. to FRIS and the first author of the article.

In collaboration with Amy Shen, head of the Micro/Bio/Nanofluidics Unit at OIST, the Tohoku-OIST interdisciplinary team conducted simulations and experiments to visualize fluid flows in spiral structures. Daniel Carlson from Shen’s team said: “We confirmed the presence of Dean vortices, a type of rotational flow occurring in curved channels, in our devices, affirming their potential to significantly improve the efficiency of the separation of cells and particles. »

“Rapid prototyping of three-dimensional spiral microfluidics using mini-rTDP represents a remarkable advancement in the field of microfluidics. This technology offers unparalleled versatility, precision and potential to catalyze transformative changes in various industries,” says Shen.

“In addition, we are actively pursuing the integration of microfluidic channels with features such as electrodes, biosensors and actuators directly into fibers. This effort has the potential to revolutionize lab-on-a-chip bioanalytical technologies,” said Guo .

This research demonstrates the collaborative efforts of the OIST SHIKA program and matching funds provided by Tohoku University, highlighting the strong partnership and synergy between these two institutions.