Multidimensional Paper Networks: A New Generation of Low‑Cost Pump‑Free Microfluidic Devices

Abstract

Since Andreas Manz first introduced the microchip technology
for chemical applications back in the 1990s, the field of ‘microfluidics’
has expanded widely and microfluidic tools have become ubiquitous
in life sciences research. However, pumps and controllers associated
with most current microfluidic chips continue to be bulky and costly. A
new class of microfluidic devices in which flow channels are composed
of multidimensional (2D or 3D) shapes of porous materials is becoming
increasingly popular. The ability of porous materials to wick fluids obviates
the need for pumps, making such devices portable, low-cost, and
ideal for use in low-resource settings. Such devices are broadly referred
to as “paper microfluidic devices”. The ability to manipulate fluids in
paper microfluidics has progressively increased over the past decade
and such devices are currently being used to develop highly sensitive
and multiplexed low-cost diagnostic/sensing devices. In this article, we
review the area of paper microfluidics covering the basic fluid physics,
methods of fabrication, flow control tools, applications in diagnostics/
sensing, and applications in other emerging areas like tissue engineering
and power storage. This review is targeted to a broad audience that
does not have prior exposure to the field of paper-based microfluidics.
Through this article, we wish to invite researchers from multiple backgrounds
to contribute to further development in this new and exciting
area of research.