The field of separation science is driven by the desire to create discrete pure analyte populations with increasingly similar properties. Utilizing trapping and streaming dielectrophoresis (DEP), separations are achievable by exploiting the subtle differences in electrophysical properties of analytes. Insulator-based DEP (iDEP) uses various insulator shapes in microchannels to achieve the non-uniform electric fields necessary for DEP. This technique has been used to manipulate a variety of analytes including polystyrene spheres, cells, bacteria, proteins, DNA, and viruses. Current insulator shapes include triangles, diamonds, circles, and rectangles. These insulator shapes do not induce consistent forces across the lateral dimension of the channel, ultimately posing problems for trapping, streaming, and sorting (deflection). The lateral inconsistencies lead to analytes experiencing different forces depending upon their pathline in the microchannel, and thus result in low resolution separations.<br/>An iterative process of modelling and comparing approximately 40 different insulator shapes was used to help determine a design that improves particle streamlines, trapping efficiency, and induces laterally-similar environments. The designs were assessed by calculating and plotting the electric field, gradient of the electric field squared, and the ratio of the two. A novel multi-length scale element was added which results in streamlining of analyte(s) and improves the homogeneity in the lateral dimension, while still achieving high enough gradients necessary for analyte separations using negative DEP. The design will improve the resolution of separation for iDEP and eliminate extraneous trapping zones. Comparisons of the forces and capture locations in microfluidic channels for current and the improved geometry will be presented.

Models of refined separations using insulator-based dielectrophoresis

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.