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, 30 pairs of asymmetrical electrodes were employed in the pumping region; generated ACET velocity was measured by fluorescent microparticle 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.
Keywords: AC electrothermal; cell culture; circulatory pumping chip; human-on-a-chip; microfluidics.