Microfluidics

In the recent breakthrough of stem cell researches, somatic cells can be reprogrammed to pluripotent states or be converted to other cell lineages by delivery of transcription factors, RNA or small molecules. The first challenge to overcome is to deliver molecules cross cell membrane. Several delivery methods, such as viral infections, lipid-mediated transfections and electroporations, are widely applied due to their robustness and large-scale operation. However, the spatial and temporal controls are hard to achieve due to stochastic nature of bulk processes. Here we developed a...

Sample capture transport of biological fluids, like blood flow in diabetes glucose monitors, often requires microfluidic actuation. Current commercial methods used in diabetes glucose monitors usually involve porous materials or hydrogels, but these strategies are limited in fluid control. Surface wettability gradient actuation is an approach widely used in various other microfluidic or lab-on-a-chip systems. Here we design and fabricate a droplet-actuation device that relies purely on capillary pressure gradients induced by surface topologies. We discuss the theoretical capabilities...

Single cell analysis is an increasingly important area of consideration. Rather than obtaining a bulk average assay result from a large number of cells, it is possible to do a statistical study on each individual cell in a population. Flow cytometry allows this methodology, but is incapable of testing for compounds inside the cells themselves. It instead relies on using surface markers. Some limited markers (calcium probes) capable of penetrating the cell wall are also available, but are limited to a few very specific tests. Our device will enable the assay of cytosolic (internal)...

Tumor chemo-sensitivity assays (TCA) involve the in vitro exposure of cultured cancerous cells to different drugs at varying concentrations. These analyses are traditionally used to determine drug susceptibilities, of cancerous cells in vitro, and can help discern whether a certain drug regimen will work against a tumor of a certain individual. This paradigm of personalized medicine has been explored in breast cancer, where a correlation has been shown between TCA guided therapy and clinical outcome. Microfluidic platforms can provide clinicians the ability to perform such assays...