Dielectrophoresis (DEP) has an immense potential for particle sorting and separation in microscale systems. Specifically, insulator-based dielectrophoresis (iDEP) devices are both inexpensive and effective for the analysis of biological particles or cells. In previous work, it has been seen that submicron carboxylated particles (dp < 500 nm) experience a positive DEP force when exposed to a non-uniform electric field, while larger particles (dp>1 mm) experience a negative DEP force [1]. In this research, the effect of particle surface charge magnitude on the DEP force is investigated. Two different particle surface functionalizations are also analyzed: carboxylated and aminated (negatively and positively charged, respectively). Being able to separate sub-micron particles by exploiting charge differences offers great potential in bioanalysis.

  1. Mario A. Saucedo-Espinosa Mallory M. Rauch Alexandra LaLonde Blanca H. Lapizco-Encinas, “Polarization behavior of polystyrene particles under direct current and low-frequency (<1 kHz) electric fields in dielectrophoretic systems,” Electrophoresis 2016, 37, 635–644