A nonuniform electric field induces a dipole within each neutral, polarizable particle. Because the field strength varies across space, the two ends of that dipole experience unequal electrical effects, producing a net force. The resulting movement is directed toward a stronger or weaker field region, allowing electrode-based devices to control particle position without chemical labels.
The particle’s electrical properties and the surrounding medium determine the direction of movement. Under positive dielectrophoresis, particles move toward regions of stronger electric field, whereas negative dielectrophoresis drives them toward weaker regions. This distinction matters because changing the electrical relationship between the particle and medium can alter where cells or microscale materials accumulate within a device.
Dielectrophoretic behavior depends on how a particle becomes polarized in relation to its surrounding medium. Those electrical properties influence both the magnitude and direction of the force generated by the nonuniform field. In bioengineering experiments, accounting for this relationship helps determine whether a device will concentrate, trap, sort, or otherwise reposition cells and microscale materials.
A typical workflow places the cells or microscale materials in a microfluidic environment containing electrode structures, then applies a nonuniform electric field. The induced forces move particles toward stronger or weaker field regions according to their electrical properties and the medium. Researchers can then use the controlled positioning for sorting, concentration, trapping, patterning, or characterization.
Researchers may choose dielectrophoresis when they need label-free control of cells or microscale materials inside a microfluidic device. Its capabilities support sample preparation and diagnostics, while also enabling concentration, sorting, trapping, and patterning. The same approach can contribute to tissue-engineering workflows and investigations of cell viability or phenotype without requiring chemical labels.
Electrode-based systems can reveal how cells or microscale materials respond to an applied nonuniform electric field by producing controlled changes in their location and organization. These outcomes include separation, concentration, trapping, pattern formation, and characterization. In bioengineering, such responses can support studies of cell viability and phenotype as well as practical sample-handling steps.