Microfluidics

Microfluidic polymerase chain reaction (PCR) has been of great interest owing to its ability to perform rapid and specific nucleic acid amplification and analysis on small volumes of samples. One of the major drawbacks of microfluidic PCR is bubble generation and reagent evaporation, which can cause malfunctions. Here, we propose a bubble-free microfluidic PCR device via controlled fluid transfer. We design the PCR chamber surrounding circumferential chamber allows a guided-fluid transport of generated bubble to circumferential chamber through thin nanoporous PDMS sidewall. We...

Mixing in microfluidic devices has long presented challenges due to the lack of significant turbulence at low Reynolds numbers. Although ample theoretical work has demonstrated methods to enhance microfluidic mixing (e.g., increasing vorticity, arranging chaotic flow profiles), many of these methods are difficult to achieve in practical microfluidic devices, requiring 2D approximations to fully 3D mixing enhancements. In this work, we will show that various designs for enhanced mixing are easily achievable using 3D printing. We will compare the performance of several different mixer...

In this work, we demonstrate the use of 3D-printed molds for fabricating PDMS-based microfluidic devices. 3D Printing allows for the fabrication of molds that are not monolithic in structure, and therefore represents a significant improvement over the capabilities of standard soft lithography; with 3D-printed molds, we can fabricate most features commonly generated by soft lithography in addition to formerly difficult features such as domes and variable-sized channels. Furthermore, we demonstrate that this technique can be used to generate microfluidic devices molded on both sides -...

The unique properties of blood flow in microchannels has been studied for nearly a century; much of the observed blood-specific dynamics is attributed to the biconcave shape of red blood cells. However, for almost twice as long biologists have observed and characterized the differences in size and shape of red blood cells among vertebrates. With a few exceptions, mammals share the denucleated biconcave shape of erythrocytes but vary in size; oviparous vertebrates have nucleated ovoid red blood cells with size variations of a full order of magnitude. We utilize micro-PIV and pressure...