471712 Reversible Assembly of Colloidal Particles Using Low Frequency Pulsed DC Electric Fields for Electrophoretic Displays

Wednesday, November 16, 2016: 10:45 AM
Embarcadero (Parc 55 San Francisco)
Elaine Lee1, Jessica Dudoff1, Hannah Coe1, Brian Giera1, Marcus Worsley1, Joshua D. Kuntz2, Luis A. Zepeda-Ruiz3 and Andrew J. Pascall4, (1)Lawrence Livermore National Laboratory, Livermore, CA, (2)Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, (3)Chemistry and Material Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, (4)Materials Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA

We present the reversible assembly of colloidal nanoparticles in organic solvents using low voltage and low frequency pulsed DC electric fields. Commercially available and custom nanoparticles (diameter ~ 50-200 nm) were suspended in organic solvents at concentrations of 0.25-50 wt% and sandwiched between indium tin oxide (ITO) electrodes of spacing 25 μm-2mm. Using square waves of frequency 0.25-5 Hz, voltages 0.5-5V, and DC offset 0.25-2.5V, colloidal suspensions were actuated for switchable contrast. Upon switching off the electric field, the assembled nanoparticles are able to resuspend within seconds. Using patterned electrodes, lateral electromigration of the particles was demonstrated. Depletion of the particles to the electrode regions resulted in transparency in the non-patterned regions. The distinct contrast generated can be exploited for tunable display applications. We will also present a particle-based numerical model of the deposition and resuspension processes.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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See more of this Session: Electrokinetics: Advancing the Fundamentals II
See more of this Group/Topical: 2016 Annual Meeting of the AES Electrophoresis Society