Kyushu University Innovates with Plant-Based Microfluidics for Complex 3D Networks

Microfluidic technology is increasingly vital across numerous scientific fields, including regenerative medicine and environmental science, yet traditional microfabrication techniques often struggle with the scalability and complexity needed for building intricate three-dimensional networks. Researchers at Kyushu University propose an innovative solution inspired by nature: using plants and fungi to overcome these hurdles.

Led by Professor Fujio Tsumori from Kyushu University's Faculty of Engineering, the team has developed a novel technique utilizing the natural growth patterns of plant roots and fungal hyphae. The process involves cultivating these organisms in a specially designed "soil" medium composed of glass nanoparticles and cellulose-based binders. Once the plants have formed their root structures, they are carefully removed, leaving behind micrometer-sized hollow cavities in the glass that serve as complex 3D microfluidic networks.

This groundbreaking method not only advances microfluidic technology but also offers new avenues for studying and preserving 3D biological structures typically difficult to observe in natural soil environments. The details of their research have been published in the journal Scientific Reports.

"The primary motivation for our research was to address the limitations of existing microfabrication techniques in crafting complex 3D microfluidic structures," explains Professor Tsumori. "Our lab focuses on biomimetics—we seek engineering solutions by mimicking nature and replicating such structures artificially."

The intricacy of natural microfluidics found in plant roots and fungal hyphae served as the perfect model. The research involved developing a soil-like substrate mixed with minuscule glass nanoparticles and hydroxypropyl methyl cellulose. After successful plant growth, the "soil" is baked in a process called sintering, solidifying the glass nanoparticles into durable structures with empty root channels.

This method successfully replicates intricate biological structures ranging from large main roots to tiny root hairs of around 8 μm in diameter, with experiments showing similar results for fungal hyphae, which can measure as small as 1-2 μm. The comparison provided structural insights for rye plant vasculature alongside koji Aspergillus oryzae morphologies, illustrating channels as thin as 10 μm in plant roots and 2 μm in fungal hyphae.

"Our refined technique could offer significant advantages in various scientific domains, potentially leading to breakthroughs in microreactors, heat exchangers, and tissue engineering scaffolds," Tsumori suggests.

Beyond engineering applications, this technique also offers unique tools to deepen biological studies, particularly in understanding complex 3D structures within soil ecosystems. By merging biological insights with engineering innovation, Kyushu University's research is poised to unlock new scientific possibilities and technological advancements.