3D Printed Paper-Based Microfluidic Analytical Devices.

Yong He,Jing Nie,Jian-Zhong Fu,Wen-Bin Wu,Qing Gao

doi:10.3390/mi7070108

Abstract

As a pump-free and lightweight analytical tool, paper-based microfluidic analytical devices (μPADs) attract more and more interest. If the flow speed of μPAD can be programmed, the analytical sequences could be designed and they will be more popular. This reports presents a novel μPAD, driven by the capillary force of cellulose powder, printed by a desktop three-dimensional (3D) printer, which has some promising features, such as easy fabrication and programmable flow speed. First, a suitable size-scale substrate with open microchannels on its surface is printed. Next, the surface of the substrate is covered with a thin layer of polydimethylsiloxane (PDMS) to seal the micro gap caused by 3D printing. Then, the microchannels are filled with a mixture of cellulose powder and deionized water in an appropriate proportion. After drying in an oven at 60 °C for 30 min, it is ready for use. As the different channel depths can be easily printed, which can be used to achieve the programmable capillary flow speed of cellulose powder in the microchannels. A series of microfluidic analytical experiments, including quantitative analysis of nitrite ion and fabrication of T-sensor were used to demonstrate its capability. As the desktop 3D printer (D3DP) is very cheap and accessible, this device can be rapidly printed at the test field with a low cost and has a promising potential in the point-of-care (POC) system or as a lightweight platform for analytical chemistry.

Highlights

As a lightweight analytical tool, paper-based microfluidic analytical devices have attracted increased interest and attention [1], which has led to their rapid development since Whitesides et al [2] introduced the μPADs concept in 2007
Compared to conventional microfluidic chips made of glass and polymer substrates, μPADs have some unique advantages including, low cost, ease of fabricate, strong capillary action and good biological compatibility for applications in point-of-care (POC) diagnosis, food quality and environmental monitoring [3,4]
If the flow speed of μPADs can be programmed, the analytical sequences could be designed and they can be more used for performing multistep tasks or handling complex chemical matrixes

Summary

Introduction

As a lightweight analytical tool, paper-based microfluidic analytical devices (μPADs) have attracted increased interest and attention [1], which has led to their rapid development since Whitesides et al [2] introduced the μPADs concept in 2007. Many studies have explored fabrication techniques for μPADs including wax printing [5,6,7], inkjet printing [8,9], ink stamping [10,11], dynamic mask photo curing [12], paper cutting [13] and ink permanent markers [14] etc It is an ideal substrate for controlling flow and for confining liquids to specified areas without external pump on the paper. Since the D3DP may become as popular as the personal computer [40], this kind of microfluidic device can be rapidly manufactured in a common office, which is very suitable for the POC system As this analytical device has the same working principle as the μPAD, and they can be directly 3D printed, we called this device as a μ3DPAD. Some analytical applications were used to prove that μ3DPADs can be a good supplement of μPADs

Materials

Speed Programing by Adjusting Channel Depth

Encapsulation of the μ3DPADs