Externally Tunable, Low Power Electrostatic Control of Cell Adhesion with Nanometric High‐k Dielectric Films

Controlling cell adhesion to surfaces is an important, but difficult, problem. Current methods to control adhesion rely on surface functionalization, which have limited material choice to avoid cell toxicity and are typically cell specific. Herein, cell adhesion is modulated by using nanometric high‐k dielectric films. Voltage is applied across the dielectric film, changing the film surface's zeta potential, ζ. High performance dielectrics, HfO 2 and SiO 2 , enables a change in the ζ polarity and magnitude over large, 100 mV, ranges by applying ≈1 V across the dielectrics with ≈1nW power draw. Freshwater Chlorella vulgaris and saltwater Nannochloropsis oculata, which have a negative ζ, are used as model cells. Cell adhesion is observed to be inhibited when both surface and cell ζ are negative and enhanced when surface ζ is positive and cell ζ are negative using microfluidic experiments. Finally, millimetric scale cell patterning is demonstrated by spatially modulating ζ with no observed toxicity to cells over 4 weeks.