AC electrothermal circulatory pumping chip for cell culture.

Herein we describe a novel AC electrothermal (ACET) fluidic circulatory pumping chip to overcome the challenge of fluid-to-tissue ratio for "human-on-a-chip" cell culture systems. To avoid the deleterious effects of Joule heating and electric current on sample cells, a rectangular microchannel was designed with distantly separated regions for pumping and cell culture. Temperature variations were examined using a commercial thermocouple sensor to detect temperature values in both pumping and culture regions. To generate a sufficient ACET circulatory pumping rate, thirty pairs of asymmetrical electrodes were employed in the pumping region; generated ACET velocity was measured by fluorescent micro-particle image velocimetry. The benefits of our pumping chip were demonstrated by culturing human embryonic kidney cells (HEK293T) and human colon carcinoma cells (SW620) for 72 h with an energized voltage of 3 V and 10 MHz. Cells grew and proliferated well, implying our ACET circulatory pumping chip has great potential for cell culture and tissue engineering applications.