(4cn) Assembly, Manipulation, and Controlled Release of Complex Nanocolloids by Dielectrophoresis

Alternating current (AC) electric fields have been widely applied to particles and cells of micron size as an efficient and effective assembly strategy using typical electrokinetic techniques, such as dielectrophoresis. However, many technologies, such as targeted drug deliver and lab-on-a-chip diagnostics, will also require the manipulation of nanocolloids of sizes not previously studied. Here, I provide robust experimental evidence of the simple assembly and manipulation of nanoparticles, which has not been previously reported. In addition, the polarization of complex biocolloids, namely micelles and liposomes, has been studied with intriguing results, and I present the strong dependence of colloid concentration on AC-field frequency. Finally, I find a distinct frequency induced encapsulate release from micelle interiors with a dependence on the surfactant-encapsulate interaction. The fundamental understanding of polarization as well as the potential for this work in targeted, controlled drug delivery and medical diagnostics provides an exciting landscape for new materials in AC-electrokinetic studies.