Unveiling innovation: Microwave-microfluidic sensors for monitoring microplastics in aquatic environments
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By Maziar ShafieiDarabi
Microplastics, pervasive pollutants in aquatic ecosystems, present a pressing challenge for researchers striving to understand and mitigate their impact. Amidst this challenge arises a new technology: microwave-microfluidic based sensors. This article delves into the transformative potential of these sensors in the realm of microplastic research.
Maziar ShafieiDarabi, PhD Candidate, Waterloo Microfluidics Laboratory, Faculty of Engineering
Traditionally, microplastics research has depended on laborious and time-consuming techniques. However, emerging methods offer significant improvements, particularly in simplifying the sample preparation process. Leading this innovation are microwave-microfluidic based sensors, which integrate microwave technology with microfluidic systems to detect microplastic pollutants in environmental samples.
So far, microwave-microfluidic sensors have shown promise in characterizing environmental samples based on size and concentration, while also accounting for crucial environmental factors like temperature. They demonstrate proficiency in specific scenarios; however, it is imperative to acknowledge their limitations and identify situations where alternative methods may be more suitable for characterizing and identifying microplastics. For instance, current microwave-microfluidic sensors lack the capability to determine the type of polymer used in the microplastic or monitor very low concentrations of microplastics in the sample. They also cannot discern the shape of the microplastic or its surface roughness. If these parameters are critical for your analysis, alternative methods should be explored. These alternative methods might be more time-consuming, labor-intensive, and require complicated sample preparation procedures.
Graphic abstract
However, the optimization of microwave microfluidic sensors for microplastic monitoring applications is still in its early stages, with much progress yet to be made. Our future research will prioritize enhancing performance and improving the limit of detection by redesigning the microwave structure and microfluidic platform, upgrading sensor materials, and integrating the sensor with portable measurement circuitry to develop a portable microwave-microfluidic-based microplastic sensing system. Additionally, we are exploring methods such as enhancing microplastic concentration in samples through techniques like external filtering and on-chip concentration using microfluidic approaches. We also highlight the optimization of the microwave sensor's design, especially the split-ring resonator with a smaller gap size, to achieve improved sensitivity and specificity in detecting microplastics. Furthermore, we aim to leverage the multiplexing capability for enhanced selectivity and single-particle sensing.
As microplastics persist in infiltrating our environment, the need for innovative solutions has never been more urgent. Microwave-microfluidic based sensors provide a ray of hope in on-field microplastic monitoring, transforming the trajectory of microplastic research and propelling us towards a more profound comprehension of this vital environmental concern. By understanding their capabilities and integrating them with traditional methods, we explore new avenues of discovery, paving the way for a cleaner, healthier and safer future.
This research is supported by a NSERC Alliance Grant under the Plastics science for a cleaner future program. Maziar’s work is contributing to the project, "Microplastics Fingerprinting at the watershed scale: from sources to receivers" led by Principal Investigator Philippe Van Cappellen.
Listing photo: Microplastic in cosmetics by Costantina Cossu