Electrically Programmable Surfaces for Configurable Patterning of Cells

Microsystems technology provides the ability to precisely control micrometer-scale environments that surround cells in microfluidic devices, small-volume chambers, or biochips. Precise control over the chemical and cellular environment, including interactions with neighboring cells, in microdevices opens doors to new high-throughput and high-content experimental approaches and mechanistic insights into cell behaviors, such as relationships between cell shape and cell growth. Fundamental aspects of complex cell–cell interactions found in living organisms can also be re-created in microsystems for drug and toxicology screening. To create and accurately control the environmental and physiological conditions, surfaces capable of generating micrometer-scale patterns of cells in microsystems are crucial. These surfaces serve for controlling cellular growth factors, engineering tissues, and performing controlled cell-based assays, and could become key components for the development of bioelectronics and portable diagnostic devices useful in clinical settings. In this Communication, we present a newmaterial approach that can be programmed to generate cell patterns on a surface, with the smallest dimension down to the size of single cells. The locations and shapes of the generated cell patterns on a surface can be controlled externally by selectively switching on microelectrode arrays in an engineered microfluidic device. In addition, the method allows one to configure different cell population densities and cell morphologies into generated cell patterns on the same surface by adjusting applied voltage biases on the microelectrodes. Several techniques have demonstrated an ability to immobilize cells on designated regions on a surface. For example, cell patterns have been generated by using microcontact