Abstract

In contrast to standard microfluidics, which are typically closed, we are developing a scanning, non-contact microfluidic technology that can shape liquids in the "open space" over surfaces. This technology utilizes a microfluidic probe (MFP) having microfabricated structures for localizing a liquid of interest on a surface using hydrodynamic flow confinement. MFP permits patterning surfaces with proteins and other biomolecules in an additive and subtractive manner, forming complex gradients on surfaces, and interacting with cells on surfaces. With flow confinement operating at volumes smaller than 1 nanoliter, a few cells can be targeted in a human tissue section for the specific staining of disease markers.  This confinement concept has also been scaled for targeting 1000’s of cells. Flow confinement and efficient use of chemicals can be further optimized using a concept called "hierarchical" hydrodynamic flow confinement.  I will show how this family of liquid scanning probe devices is evolving as a bioanalytical tool to alter the physics and chemistry of biological interfaces at the micrometer to centimeter-length scales. I will also propose concepts pertaining to tissue microprocessing encompassing local phenotyping for interrogating tumor heterogeneity and spatially resolved molecular profiling which may contribute to the multi-modal analysis of critical biopsy samples in the context of next-generation pathology.