Brendan D MacDonald

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We present a low cost, simple and integrated device for medical diagnostics in low-resource settings called the lab-in-a-pen. Finger pricking, and sample collection and processing, are integrated with commercially available paper-based assays in a pen format. This approach ensures safety (i.e. biological sample and sharps containment) and can be used by(More)
Low-cost paper-based assays are emerging as the platform for diagnostics worldwide. Paper does not, however, readily enable advanced functionality required for complex diagnostics, such as analyte concentration and controlled analyte transport. That is, after the initial wetting, no further analyte manipulation is possible. Here, we demonstrate active(More)
In this paper, we present an on-chip hand-powered membrane pump using a robust patient-to-chip syringe interface. This approach enables safe sample collection, sample containment, integrated sharps disposal, high sample volume capacity, and controlled downstream flow with no electrical power requirements. Sample is manually injected into the device via a(More)
We present a scalable, out-of-plane desalination approach using ion concentration polarization. A depletion boundary separates salt ions and purified water into distinct vertical layers. The out-of-plane design enables multiplexing in three dimensions, providing the functional density required for practical application. For membrane widths of 125-200 μm,(More)
In this work we describe a fabrication method to create compact and microscale features in paper-based microfluidic devices using a CO2 laser cutting/engraving machine. Using this method we are able to produce the smallest features with the narrowest barriers yet reported for paper-based microfluidic devices. The method uses foil backed paper as the base(More)
In this paper we experimentally examine evaporation flux distributions and modes of interfacial energy transport for continuously fed evaporating spherical sessile water droplets in a regime that is relevant for applications, particularly for evaporative cooling systems. The contribution of the thermal conduction through the vapor phase was found to be(More)
In this paper, we present a low cost and equipment-free blood filtration device capable of producing plasma from blood samples with mL-scale capacity and demonstrate its clinical application for hepatitis B diagnosis. We report the results of in-field testing of the device with 0.8-1 ml of undiluted, anticoagulated human whole blood samples from patients at(More)
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