Thuo, Martin M.Martinez, RLan, Wen-JieLiu, XinyuBarber, Jabulani RandallAtkinson, Manza B. J.Bandarage, DinethBloch, Jean-FrancisWhitesides, George2016-03-112014Thuo, Martin M., Ramses V. Martinez, Wen-Jie Lan, Xinyu Liu, Jabulani Barber, Manza B. J. Atkinson, Dineth Bandarage, Jean-Francis Bloch, and George M. Whitesides. 2014. “Fabrication of Low-Cost Paper-Based Microfluidic Devices by Embossing or Cut-and-Stack Methods.” Chem. Mater. 26 (14) (July 22): 4230–4237. doi:10.1021/cm501596s.0897-4756http://nrs.harvard.edu/urn-3:HUL.InstRepos:25811019This communication describes the use of embossing, and “cut-and-stack” methods of assembly, to generate microfluidic devices from omniphobic paper, and demonstrates that fluid flowing through these devices behaves similarly to fluid in an open-channel microfluidic device. The porosity of the paper to gasses allows processes not possible in devices made using PDMS or other non-porous materials. Droplet generators and phase separators, for example, could be made by embossing “T”-shaped channels on paper. Vertical stacking of embossed or cut layers of omniphobic paper generated three-dimensional systems of microchannels. The gas permeability of the paper allowed fluid in the microchannel to contact and exchange with environmental or directed gases. An aqueous stream of water containing a pH-indicator, as one demonstration, changed color upon exposure to air containing HCl or NH3 gases.en-USmicrofluidicsomniphobic paperembossingcut-and-stackpaper-based microfluidicsJournal Article2016-03-1110.1021/cm501596s