Society heavily relies on diverse fluidic technologies for various applications, but designing a platform for switchable capture and release of liquids with precise control has been a long-standing challenge. Recently, researchers at The Polytechnic University of Hong Kong have developed a new method to overcome this challenge, called “Connected Polyhedral Frames” (CPFs). This fluidic processor allows for reversible, programmable, and independent liquid capture and release, making it a meta-metamaterial with versatile functions. CPFs have been published in Nature Chemical Engineering, with Dr. ZHANG Yiyuan as the first author.
While solid manipulation is highly developed, handling fluids remains a cumbersome task, leading to issues such as incomplete liquid transfer, impaired volumetric accuracy, and inter-sample contamination. Disposable plastics like pipettes and microtubes are commonly used to preserve fluid purity, contributing to plastic waste. CPFs offer a solution by enabling precise processing of liquids through reversible switching between capture and release, allowing for local, dynamic, and reversible liquid retention or drainage.
CPFs provide a versatile platform for various functions, including 3D programmable patterning of liquids, 3D spatiotemporal control of material concentrations, packaging of 3D liquid arrays, and large-scale manipulation of multiple liquids. They are compatible with a broad range of liquids, making them suitable for incorporating diverse biomaterials and chemicals for various applications. By controlling the thickness of gel membranes, CPFs can precisely pattern the release rates of different drug molecules.
CPF’s superiority as a sampling tool over traditional methods was demonstrated using the influenza virus as an example. CPFs showed significantly better release performance, especially at low virus concentrations, compared to cotton swabs and flocking swabs. CPFs were also demonstrated to be effective in biomaterial encapsulation, with advantages such as simplifying microbial reaction processes, enhancing bacterial utilization rates, and separating bacteria and reaction products efficiently.
In addition to medical and microbial applications, CPFs have been applied in air conditioning for better humidification and energy efficiency. A commercial-scale humidifier prototype using CPFs showed higher water storage capacity and required less water flow, making it potentially more energy efficient. CPFs also allow for large-scale 3D liquid dispersion, making them useful for gas absorption applications such as carbon capture, storage, and reutilization. The innovative design of CPFs allows each frame to independently capture or release liquids, making it a groundbreaking meta-metamaterial with high performance and versatility.
The availability of CPFs as a fluidic processor sets a new standard for handling liquids with controllability, versatility, and high performance. It inspires a new field of meta-metamaterials and facilitates scientific and technological breakthroughs in various fields. The design of CPFs enables precise liquid processing in various applications, ranging from medical and pharmaceutical settings to air conditioning and environmental applications. The innovative approach of CPFs opens up new possibilities for handling fluids with unprecedented control and efficiency.