(395d) Effect of Insulator Post Shape on Joule Heating Effects in Insulator-Based Dielectrophoretic Devices

Insulator-based dielectrophoretic (iDEP) devices have shown great potential and versatility for biotechnological applications. Our group has been working on identifying the best design characteristics to increase the efficiency of particle manipulation inside microchannels with insulators. We learned in 2014 [1] that geometries with sharp edges produce an overall higher () that leads to lower voltage requirements to achieve dielectrophoretic trapping. In 2015 we reported a follow up study [2] where we analyzed more in depth the effect of the posts’ geometry on particle trapping by means of dielectrophoresis; this study allowed identifying optimal geometries that produce good particle trapping at much lower voltages. However, as the amount of trapping sites was significantly increased in the optimized geometries (in comparison to conventional geometries), there is a concern as to whether this will also produce an important rise in the sample temperature. This study compares the Joule heating generated in optimized, sub-optimal and standard insulating post shapes by analyzing values of the gradient of the electric field squared, temperature, and magnitude of particle trapping. A 3D model was evaluated, which allowed dissipation of heat for all sides of the microchannel, and experimental validation of the model was performed by employing Rhodamine B, a temperature dependent dye.

1. LaLonde, A., et al., Effect of insulating posts geometry on particle manipulation in insulator based dielectrophoretic devices. Journal of Chromatography A, 2014. 1344(0): p. 99-108.

2. Saucedo-Espinosa, M.A. and B.H. Lapizco-Encinas, Design of insulator-based dielectrophoretic devices: Effect of insulator posts characteristics. Journal of Chromatography A, 2015. 1422: p. 325-333.