Controlled rotation and vibration of patterned cell clusters using dielectrophoresis.

The localized motion of cells within a cluster is an important feature of living organisms and has been found to play roles in cell signaling, communication, and migration, thus affecting processes such as proliferation, transcription, and organogenesis. Current approaches for inducing dynamic movement into cells, however, focus predominantly on mechanical stimulation of single cells, affect cell integrity, and, more importantly, need a complementary mechanism to pattern cells. In this article, we demonstrate a new strategy for the mechanical stimulation of large cell clusters, taking advantage of dielectrophoresis. This strategy is based on the cellular spin resonance mechanism, but it utilizes coating agents, such as bovine serum albumin, to create consistent rotation and vibration of individual cells. The treatment of cells with coating agents intensifies the torque induced on the cells while reducing the friction at the cell-cell and cell-substrate interfaces, resulting in the consistent motion of the cells. Such localized motion can be modulated by varying the frequency and voltage of the applied sinusoidal AC signal and can be achieved in the absence and presence of flow. This strategy enables the survival and functioning of moving cells within large-scale clusters to be investigated.