Rapid prototyping of paper‐based microfluidics with wax for low‐cost, portable bioassay

Abstract

Here we present a simple and low-cost production method to generate paper-based microfluidic devices with wax for portable bioassay. The wax patterning method we introduced here included three different ways: (i) painting with a wax pen, (ii) printing with an inkjet printer followed by painting with a wax pen, (iii) printing by a wax printer directly. The whole process was easy to operate and could be finished within 5-10 min without the use of a clean room, UV lamp, organic solvent, etc. Horse radish peroxidase, BSA and glucose assays were conducted to verify the performance of wax-patterned paper.

Paper-based microfluidic devices by asymmetric calendaring

“…To validate the capability of fabricated channels as microfluidic devices, a "Y" design was used for fluid flow and theoretically compared with the literature (Figures 3(a)-3(c)). 5,8,10,11,14,16,18,20,[37][38][39][40][41][42][43] Other geometries were also fabricated (Figures 3(d) and 3(e)) to show the versatility of the targeted asymmetric calendaring and hydrophobization (TACH) method. The microfluidic devices were manufactured using paper and tested with dyed water (food color) for visualization.…”

“…5,[8][9][10][11][12][13][14][15][16][17][18][19][20][21] A range of methods have been developed to control its wetting properties, such as surface modification through particle deposition, wax printing, and sol-gel techniques, among many others. 8,9,16,[22][23][24][25][26][27] Paper as a material is asymmetric in its porosity across the thickness, a feature that is a consequence of the preparation methods. The core of a paper is often significantly denser than the surfaces, allowing most of the compressive deformation to be driven by an increase in surface fiber density (decreased surface void volume) to match that of the core-as demonstrated in calendaring (Figure 1(a)).…”

Laser-based patterning for fluidic devices in nitrocellulose

“…[3][4][5] In addition, porous nitrocellulose membranes, since their first demonstration in the 1960s, have been widely used, due to some key features, such as their smooth surface, uniform pore size, and high proteinbinding capability. 6 A large number of biological assays, namely, blotting assays, flow-through assays, and lateral flow tests have been developed on these porous nitrocellulose membranes, and hence nitrocellulose-based microfluidic devices are currently regarded as the alternative of choice for improving the performance of existing POC assays.…”

Defining microchannels and valves on a hydrophobic paper by low-cost inkjet printing of aqueous or weak organic solutions

“…As a result, lPADs have emerged as a promising platform for point-of-care analytical applications in clinical diagnostics, [1][2][3] food safety control, 4,5 and environmental testing. 6,7 Various techniques have been used to fabricate lPADs, including photolithography, 8,9 wax printing, [10][11][12] inkjet printing, [13][14][15] laser etching, 16,17 plasma treatment, 18 and use of metal/paper masks. [19][20][21][22][23] Each technique has particular advantages and drawbacks.…”