The weaving of the carbon fiber using induced-charge electro-osmosis with DC–AC alternating switching

Abstract

Controlling the self-organizing structure is important for the use of self-organizing materials in a variety of applications. Here, we report the weaving method of the carbon fiber using induced-charge electro-osmosis (ICEO) with DC–AC alternating switching treatment. Specifically, we report that the spread low-density carbon fibers having a dendritic structure grow by applying a DC voltage, while the spread fibers shrink irreversibly with contacting and entangling by applying an AC voltage. Consequently, a weaving structure of carbon fibers can be achieved. Although the micro-scale weaving technology for polymers has been developed mainly in the field of tissue engineering, the weaving technology for conductive carbon fibers that can be used as a cilium-like ICEO actuator in a microfluidic circuit has not been explored so far; thus, we have first demonstrated that the woven structures of the conductive carbon microfibers can be made by the electrokinetic phenomena using a DC–AC alternating electric field. Moreover, through the visualization of the flow fields during the DC–AC weaving process, we clarified the mechanism of the DC–AC weaving phenomenon related to the dielectrophoresis and ICEO phenomena. Our technology should open a different design strategy to improve the structure of self-organizing materials that can be used in microfluidic circuits.