Diagnostic assays created using simple and inexpensive materials have the potential to transform healthcare management systems in resource-limited settings. This change can be caused by making assays more accessible, more affordable, or by inspiring the development of tests that do not exist currently but would solve a considerable need. Microfluidic devices produced from patterned paper have emerged as a promising candidate for a general platform capable of supporting the development of these diagnostic assays.
We are interested in two aspects of paper-based microfluidics: (i) using the inherent stackability of patterned paper to develop three-dimensional microfluidic devices and (ii) expanding the role of paper in diagnostic assays.
Adhesion and programmed changes in adhesion play critical roles in development, health, and the pathogenesis of disease. In addition, biomaterials are often characterized by their ability to promote or resist cell adhesion. The current methods of microscopy used to observe cell adhesion are either restricted to transparent substrates or require the use of fluorescent labels.
We developed lateral microscopy to observe and quantify cell adhesion. The imaging system of the lateral microscope is oriented substantially parallel to the surface of interest, which allows cells to be observed directly on any material regardless of its composition, opacity, or topography and without the need for labels. In this way, we can use a “biological analog” to surface wettability where measurements of contact angle and the rate of change in contact angle describe cell adhesion.
When mixed, many solutions of polymers, surfactants, and salts form immiscible phases. These phases order spontaneously according to density and are thermodynamically stable. The properties of each phase (and the interfaces between them) can be controlled by the careful selection of components or the addition of co-solutes.
We are interested in characterizing the properties of the interfaces between immiscible liquid phases, and applying immiscible systems to the study and self-assembly of complex mixtures. We are particularly interested in those systems that share water as a common solvent (i.e., aqueous multiphase systems).