The nanofluidic diode device was a significant ionic transistor. Its multiple cascades could realize diversified ion transport behaviors and information processing functions. Different cascade modes of channel units will affect the response current properties of multichannel systems. Inspired by independent and synergistic effects in semiconductor transistors, artificial conical nanoporous bichannel systems were investigated in separation and stacking cascade modes to discuss their different ion transport behaviors. The dynamic resistance fitting method was adopted to discuss the properties of each circuit components in the bichannel system for analyzing the circuit properties in different cascade modes. In the stacking mode, electric field interactions at the heterojunctions between channel units dominated the ionic transport properties, and response current of the bichannel system was influenced by the channel unit cascade sequence. In the separation mode, channel units transport ions independently, and the cascade sequence had little effect on response current properties of the system. These promising results provide a new strategy to design and build a series of artificial composite nanochannels with multifunction and intelligence.
Keywords: bichannel system; cascade mode; independent effect; ion transport behavior; nanofluidic diodes; synergistic effect.