A study is conducted to report an enhanced stability and controllability of ionic diode based on funnel-shaped nanochannels with a much longer critical region, which are nanosized and different with other micrometer funnel-shaped nanochannels. The polarity of ion transport switching from anion/cation-selective to ambipolar can be controlled by tuning the length and charge of the critical region. This nanofluidic structure offers a simple and flexible approach for controlling the preferential conduction of ions in fluids and has potential applications in single-molecule biosensing, water resource monitoring, and health care.
- Ion rectification
- Ionic diodes