3D Printed Paper-Based Microfluidic Analytical Devices

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.

Polycaprolactone solution–based ink for designing microfluidic channels on paper via 3D printing platform for biosensing application

“…Also, the minimum conducting width of the hydrophilic channel was found to be 460.7 ± 20 μm as shown in Figure 2F,G. Whiteside et al reported a minimum functional hydrophilic channel width of 561 ± 45 μm by wax printing whereas Yong He et al reported a minimum functional channel width of 118 ± 17 μm for 3D‐printed PDMS PAD . However, wax printing method has reported a coarse resolution and perhaps can also have nonuniformity in the hydrophobic barrier cross section .…”

“…Li et al developed yet another technique known as the print‐pause‐print (PPP) where in prefabricated components (like electrodes), which are required for the functioning of μPAD, can be added to the printed parts by suspending the printing . The use of 3D printing for the fabrication of a class of paper‐based microfluidic devices has been studied by Yong He et al where the device consists of hydrophobic area, formed by 3D printing polylactide filaments, which is coated with a layer of PDMS, and the hydrophilic channels formed by the deposition of cellulose powder . Wei Long Ng et al have studied use of integrated 3D bioprinting with miniaturized microfluidics platform in toxicology studies, which would aid in standardization of process, accurate, rapid and efficient testing, real‐time monitoring, and high throughput screening .…”

Laser direct writing of carbonaceous sensors on cardboard for human health and indoor environment monitoring

“…13 Nanomaterials including, but not limited to, carbon nanotubes, 14 graphene, 15 metal nanowires, 16 and MXene, 17 have been successfully employed to construct a variety of sensors on paper using fabrication techniques such as screen printing, 18 inkjet printing, 19 and three-dimensional printing. 20 Although promising device performance has been achieved based on these methods, challenges exist including poor scalability, time-consuming and complex procedures, or cost-ineffectiveness. 21,22 For instance, screen printing, inkjet printing, and three-dimensional printing have the capability to fabricate sensors with high scalability and efficiency.…”

A Flexible Method for Nanofiber-based 3D Microfluidic Device Fabrication for Water Quality Monitoring

“…The first technique involves the combination of multi-layer paper stacked together using patterned paper and double-sided adhesive tape (or hydrophilic spray adhesive). Holes are filled with cellulose powders to provide vertical connections between adjacent layers [22,23]. This bonding process is labor-intensive and complicated.…”