Green, Low-Cost, User-Friendly, and Elastomeric (GLUE) Microfluidics

Abstract

Micro total analysis systems (μTAS) are highly attractive across numerous fields including science, engineering, and medicine due to their portability, low power use, and efficient sample and reagent consumption. Development of fully functional microfluidic devices is based on iterative design and testing of multiple prototype microdevices, and the use of hazardous conventional microfabrication methods makes this iterative process resource-intensive and prohibitive for many users worldwide. Rapid prototyping techniques can alleviate these issues, enabling accelerated development of microfluidic structures at reduced costs, making this technology available to a broader user base, from classrooms to researchers in laboratories with limited resources. Here, we present a green, low-cost, user-friendly elastomeric (GLUE) rapid prototyping method to fabricate custom master molds for polydimethyl­siloxane (PDMS)-based microfluidic devices, using an application of water-soluble poly­(vinyl acetate) (PVAc) glue. The smallest features of the molds are on the order of 80 μm wide, with tunable height control from 10 to 60 μm. This method is capable of fabricating three-dimensional features. As a proof of concept, several microfluidic devices ranging from a droplet generator to a lifting gate pneumatic microfluidic processor were fabricated to demonstrate the versatility and applicability of our method. To the best of our knowledge, this is the first rapid prototyping process that can be used either as a print-and-peel method or as a scaffolding technique using the same process and patterning material. The simplicity and inexpensive nature of this application of PVAc glue can significantly improve the development of integrated μTAS devices, while also making microfluidics greener and accessible to researchers with limited resources and little to no experience in the field.

Microwave‐assisted processing of silicone/PMMA blends for maxillofacial prostheses

“…[30] The interest in this methodology increased in recent years since some authors have been successfully applied methods using commercial microwave ovens to achieve fast PDMS curing envisaging microfluidic applications. [31][32][33] The silicone used in this study is cross-linked by Ptcatalysed hydrosilylation reaction, that is, carried out at Si H bonds have an exponential increase when the temperature is raised from 55 C to 75 C; the reaction is completed in nearly 5 minutes, as reported by Bhattacharya and coworkers. [34] Therefore, it is reasonable to state that that PDMS crosslinking can be completed within 10 minutes, as observed in this study and that the process is accelerated by the heating effect provided by microwave irradiation.…”

“…[ 30 ] The interest in this methodology increased in recent years since some authors have been successfully applied methods using commercial microwave ovens to achieve fast PDMS curing envisaging microfluidic applications. [ 31‐33 ]…”

Merging microfluidics with luminescence immunoassays for urgent point-of-care diagnostics of COVID-19

“…However, these methods are suitable for manipulating droplets but not for massive droplet generation to meet digital immunoassays. The passive method generates droplets by adjusting the flow rate and channel structure, mainly including T-channel [ 267 , 268 ], flow focusing [ 145 , 269 ], and coaxial flow focusing [ 270 , 271 ]. Conventional droplet assays can generate a mass of monodisperse droplets but with low throughput.…”

Prospective pathways of green graphene-based lab-on-chip devices: the pursuit toward sustainability

“…They did several experiments successfully as proof of concept such as rapid protein detection etc. Speller et al [ 30 ] reported a green technique for rapid prototyping of a 3D polydimethylsiloxane (PDMS)-based microfluidic structure using white glue with minimum widths of 200 μm and adjustable heights. A tabular representation depicting the historical evolvements of green materials for fabricating the basic structure of GGLOC is shown in Table 1 .…”