One-dollar microfluidic paper-based analytical devices: Do-It-Yourself approaches

Paper-based devices for an analytical application have gained great interest among researchers due to their portability, versatility and facile interpretation. The popularity of these analytical devices is supplemented by their myriad of applications, in point-of-care health systems, environmental monitoring and food safety. However, relatively sophisticated manufacturing techniques used to create complex multiplexed systems, pose barrier between the widespread adoption of the such methods in low-cost settings. Recently, researchers have taken significant efforts towards the development of paper-based analytical devices with more emphasis on novel fabrication approaches costing <1$. Such an approach was achieved by implementing Do-It-Yourself (DIY) path by employing readily available stationaries for fabrication. Here in this review, we categorise such Do-It-Yourself (DIY) approaches and explore their further developments and challenges. Moreover, we discuss the use of various low cost or off-the-shelf equipments for the fabrication of (i) hydrophobic barriers on plain paper (ii) electrodes in detection devices, and (iii) devices porting old detection techniques on to more DIY friendly housings. Additionally, this paper also explores amalgamation of multiple DIY fabrication methods, emerging trends and prospects in the past five years.