The objective of this proposal is to develop lightweight diagnostic devices that are very inexpensive (the cost of the device, combined with the cost of its transport and use, should be less than $0.01). The devices must be simple to use in a variety of settings, including home healthcare (for monitoring chronic disease, therapy, and metabolic function); in nursing homes and schools, at athletic events, or in field military operations; by homeland security personnel, in emergency or disaster first-response; in economically less-developed regions (as a low cost method for detecting disease in individuals and in populations); and in other applications where simplicity of operation, portability, and low cost are critically important (e.g., food and water safety and quality, agriculture, environmental monitoring). This objective will be accomplished by developing new diagnostic tools based on patterned paper. Patterned paper is paper that has been partitioned into regions of hydrophilic paper separated by hydrophobic polymer. Microfluidic devices in paper have the favorable characteristics of low weight (easy to transport), ready availability (paper is abundant nearly everywhere), and ease of use (they do not require external equipment or reagents). The specific goals of this project are to (1) expand the diagnostic capabilities of paper-based microfluidic devices and (2) develop three functional paper-based microfluidic devices that can be applied directly to problems in healthcare. The first goal will be accomplished by developing devices to mix and dilute fluids in paper, by chemically modifying paper to control how biological molecules move through the device, and by developing low-cost, quantitative detection schemes based on common electronic devices. The second goal will be accomplished by fabricating devices to detect: 1) diabetes, diseases of the kidney, and urinary tract infection; 2) liver function; and 3) HIV, hepatitis B and C, chlamydia, and gonorrhoea. Relevance: By making paper-based diagnostic devices that are low cost, light weight, and easy to use, this research aims to take disease diagnostics out of clinics and into homes, where patients can monitor their health independently, and at reduced cost. Paper-based microfluidic devices may be ideal for solving some of the diagnostic issues in developing countries, as well serve as an integral component of global surveillance systems for detecting emerging disease and predicting epidemics. ? ? ?