Programming of wicking behavior of hydrogel and paper-based microfluidic device

[摘要] Paper-based microfluidics (μPADs) have been a popular choice as lateral flow tests (LFTs) platform for diagnostic purpose because of its ease of use, speed, affordability, and spontaneous fluid transport based on an intrinsic property of material. Recent developments have rapidly increased the analytical capacity and complexity of μPADs through structural enhancements and flow control techniques. In doing so, novel wicking material such as hydrogel is introduced for additional functionality and contribute to structural complexity.The design to accommodate both the functionality and complexity of the structure is, thus, getting more and more complicated, but the process is still based on a time-consuming “estimate and check” method, which requires multiple iterations. A model that can effectively adapt properties of different wicking materials in the device and predict a resulting collective flow behavior is highly desirable with growing number of constituents and capability of μPADs.Here, the pre-storage capability of reagents in hydrogel is investigated to understand the role in μPADs and a series of experiments were conducted to identify key flow parameters to build a computational model for the flow behavior prediction. Electrical circuit analogies derived from Darcy’s law and Washburn equation are used to model the fluidic behavior of μPADs. The computational model depicts flow behavior in two connected different wicking materials, paper and hydrogel, and will be a useful tool to optimize the design process and reduce tunable time to produce a functional paper-based microfluidic device. Furthermore, the functionality of the hydrogel incorporated paper-based microfluidic device was demonstrated in the LFT format to detect glucose in sample.

[效力级别] Microfluidics

[关键词] Hydrogel;Microfluidics;Flow control, Wicking behavior modeling