Low-cost microfluidics: Towards affordable environmental monitoring and assessment

Abstract

Effective environmental monitoring has become a worldwide concern, requiring the development of novel tools to deal with pollution risks and manage natural resources. However, a majority of current assessment methods are still costly and labor-intensive. Thanks to the rapid advancements in microfluidic technology over the past few decades, great efforts have been made to develop miniaturized tools for rapid and efficient environmental monitoring. Compared to traditional large-scale devices, microfluidic approaches provide several advantages such as low sample and energy consumption, shortened analysis time and adaptabilities to onsite applications. More importantly, it provides a low-cost solution for onsite environmental assessment leveraging the ubiquitous materials such as paper and plastics, and cost-effective fabrication methods such as inkjet printing and drawing. At present, devices that are disposable, reproducible, and capable of mass production have been developed and manufactured for a wide spectrum of applications related to environmental monitoring. This review summarizes the recent advances of low-cost microfluidics in the field of environmental monitoring. Initially, common low-cost materials and fabrication technologies are introduced, providing a perspective on the currently available low-cost microfluidic manufacturing techniques. The latest applications towards effective environmental monitoring and assessment in water quality, air quality, soil nutrients, microorganisms, and other applications are then reviewed. Finally, current challenges on materials and fabrication technologies and research opportunities are discussed to inspire future innovations.

Breaking the clean room barrier: exploring low-cost alternatives for microfluidic devices

“…This article compares soft lithography, laser plotting, and 3D printing, three low-cost techniques for manufacturing microfluidic devices. Soft lithography is an affordable technique that offers high resolution and versatile geometries ( Leung et al, 2022 ; Mesquita et al, 2022 ). Laser plotting is a rapid method ( Scott & Ali, 2021 ; Šakalys et al, 2021 ), while 3D printing provides design flexibility and fast production ( Niculescu et al, 2021 ; Griffin & Pappas, 2023 ).…”

“…In general, two types of techniques can be used to manufacture microfluidic devices at a low cost: subtractive and additive techniques ( Niculescu et al, 2021 ; Scott & Ali, 2021 ; Ching et al, 2023 ). In subtractive techniques, material is removed from a substrate to create microchannels and other features, whereas in additive techniques, material is added layer by layer to build a three-dimensional structure ( Bhatia & Sehgal, 2021 ; Kulkarni, Salve, et al, 2021 ; Mesquita et al, 2022 ). Common subtractive techniques include hot embossing and laser ablation, while common additive techniques include 3D printing, soft lithography, and inkjet printing ( Bavendiek et al, 2020 ; Schneider et al, 2021a ; Grebenyuk et al, 2023 ).…”

Simple microfluidic devices for in situ detection of water contamination: a state-of-art review

“…Glass microfluidic chips are popular in health applications and life sciences because they are reusable, which helps to reduce the cost per use, while most polymeric microfluidic chips are disposable and single-use platforms. Each material has advantages and disadvantages, and the choice of material should be based on the material's integration degree with the applied application, compatibility with the chemical solutions, and cost-effectiveness, as the cost can be due to the technology used to construct the chip material (Mesquita et al, 2022), not to the material itself. This section highlights the materials used to fabricate microfluidic chips and their advantages and disadvantages.…”

Microfluidics Evolution and Surface Functionalization: A Pathway to Enhanced Heavy Metal Ion Detection

“…This balance presents a complex challenge that needs to be overcome to enhance the commercial viability of low-cost microfluidic devices in environmental monitoring. [130] The slow transition of low-cost microfluidic devices from laboratory settings to commercial products for environmental monitoring, including water quality monitoring, can be attributed to various factors, such as the reliance on external pumping systems and trained personnel, which limit their market potential. To address these challenges and facilitate the commercialization of microfluidic devices for water quality monitoring, several key considerations need to be taken into account, especially with the aid of 3D printing technology and the goal of achieving highthroughput multiplex detection with low error rates.…”