Advances of Paper-Based Microfluidics for Diagnostics—The Original Motivation and Current Status

Paper has shown potential as a ubiquitous material for fabricating micro analytical devices for diagnostic and drinking water screening applications for resource-limited regions; paper-based sensing technology has become a hot research field since 2007. Intensive research in the past decade has accumulated a large number of scientific publications. However, commercialization of microfluidic paper-based analytical devices (μPADs) for real applications is noticeably lagging behind. The “ASSURED” criteria (i.e., Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free, Deliver to the users who need them), set by the World Health Organization, specified the whole spectrum of requirements for a low-cost sensor designed for use in developing countries; they define the technical capabilities (i.e., “ASSR”) and user acceptance (i.e., “UED”) of low-cost sensing technology. While ASSR should be taken as the basic requirements of any sensor, UED determines whether or not the sensor could pote...