Experimental investigation of CNT-Based micro bubble generation inside microchannels

Abstract

Based on previous experimental results of the Carbon Nanotubes-based (CNTs-based) micro bubble generation in static water presented by our group, the dynamic characteristic of CNTs-based micro bubble will be introduced in this paper. The movement of CNTs-based micro bubble is categorized into two forms: micro bubble transportation in the micro channel driven by aqueous flow induced by the micro pump and the vibration of micro bubble on the nucleation site stimulated by the pulsed current. The CNTs-based micro bubble can be generated by micro-watt power (≪110µW) meanwhile its growth is well controlled by µA current input. Because the micro channel is used as the chamber for the micro bubble generation, the micro bubble transportation can be achieved in it. In the static water of the micro channel (i.e. there is no flow in the micro channel), the micro bubble can vibrate with frequency as the same as the input pulsed current (ƒ≪40Hz). The driving power for the micro bubble vibration can be as low as micro-watt too. The vibration distance is around 5∼10µm and during the vibration process, the diameter of the micro bubble can stay at a relatively constant value. With merits of low power consumption and the controllable vibration frequency, the movement of CNTs-based micro bubble is promising applications in future such as micro manipulation and micro actuator.