Malancha Gupta

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This article describes FLASH (Fast Lithographic Activation of Sheets), a rapid method for laboratory prototyping of microfluidic devices in paper. Paper-based microfluidic devices are emerging as a new technology for applications in diagnostics for the developing world, where low cost and simplicity are essential. FLASH is based on photolithography, but(More)
This paper demonstrates that a hand-powered egg beater can be modified to serve as a centrifuge for separating plasma from human whole blood. Immunoassays used to diagnose infectious diseases often require plasma from whole blood, and obtaining plasma typically requires electrically-powered centrifuges, which are not widely available in resource-limited(More)
This paper describes an analytical system that uses magnetic levitation to measure densities of solids and water-immiscible organic liquids with accuracies ranging from +/-0.0002 to +/-0.02 g/cm(3), depending on the type of experiment. The technique is compatible with densities of 0.8-3 g/cm(3) and is applicable to samples with volumes of 1 pL to 1 mL; the(More)
The use of delivery templates makes it possible to fabricate shaped, millimeter-thick heterogeneously patterned films of ionotropic hydrogels. These structures include two-dimensional (2-D) patterns of a polymer cross-linked by different ions (e.g., alginic acid cross-linked with Ca2+ and Fe3+) and patterns of step gradients in the concentration of a single(More)
This article describes the use of paper—patterned either by hand or with a color laser printer—to fabricate films of ionotropic hydrogels structured into regular shapes with lateral dimensions from 2 mm to several centimeters, and with thicknesses from 0.2 to 1.3 mm. Water-soluble polymers such as alginic acid (AA) and carboxymethyl cellulose (CMC) form(More)
This article describes a method for patterning certain solids—insoluble salts and reduced metals—in sheets of paper. Chemical reactions that produce these solids as precipitates occur when a stamp of patterned paper inked with an aqueous solution of reagent comes into contact with a paper substrate containing a second reagent. The pattern is determined by a(More)
The translation of batch chemistries onto continuous flow platforms requires addressing the issues of consistent fluidic behaviour, channel fouling and high-throughput processing. Droplet microfluidic technologies reduce channel fouling and provide an improved level of control over heat and mass transfer to control reaction kinetics. However, in(More)
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