Date of this Version
Schwenka, Madison. Hand-Operable Microfluidic Devices for In-field Sample Collection and Analysis. University of Nebraska-Lincoln. 2018.
Lab-on-a-Chip (LoC) microfluidic technologies provide diagnostic capabilities of use to a diversity of fields including the analytical and forensic sciences. Despite the potential benefits (e.g., on-site analysis) associated with integrating in-field sampling functionality with these devices, demonstrated applications of LoC’s in analysis and diagnostic testing generally rely on bulky external equipment (pumps and power supplies) to control the transport of analytes/samples through the devices, and in-field operation remains a challenge because this equipment is a hindrance to portability, simple packaging, and operation. The ability to integrate sampling and analysis into a single, hand-operable device could be useful for several applications in the forensic sciences (e.g., the detection of drugs, DNA, explosives, etc.). Here, the fabrication of microfluidic systems that address this issue and enable in-field sampling in solution form, thus decreasing contamination risks and eliminating post-processing extraction (which is required for sampling done using traditional methods such as swabs and wipes) was demonstrated. This work describes the evolution and testing of microfluidic devices made from soft elastomeric polymers that are designed to seal directly to multiple substrate types and to test for numerous analytes of interest. The devices reported are hand-operable and incorporated solvents within them, which, when compressed, were released into channels sealed against the substrate of interest and collected in external containers. The ability to integrate sampling with analysis provides new opportunities for the design and fabrication of LoC devices, for use by law enforcement officers, forensic scientists, military personnel, and others who are interested in in-field analytical sampling.