Stimuli-Responsive Delivery of Ions through Layered Materials-Based Triangular Nanofluidic Device

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Electrochemistry

Background:

• Biological ion channels exhibit remarkable precision in ion transport, inspiring the development of artificial counterparts.
• Existing artificial ion delivery systems often lack the accuracy required for sensitive applications.
• Nanofluidic devices offer a platform for controlled ion transport at the nanoscale.

Purpose of the Study:

• To fabricate novel iontronic devices capable of highly accurate ion delivery.
• To investigate the ion delivery rates and control mechanisms of these devices.
• To explore the potential for creating complex iontronic systems using these materials.

Main Methods:

• Fabrication of triangular nanofluidic devices using reconstructed vanadium pentoxide (VO) membranes.
• Measurement of continuous ion delivery rates for potassium (K+), sodium (Na+), and calcium (Ca2+) ions.
• Tuning ionic flow by adjusting membrane thickness and salt concentration.
• Delivery of ions in precise doses using electrothermal heating or light stimulation.

Main Results:

• The VO nanofluidic devices successfully delivered K+, Na+, and Ca2+ ions at accurate rates (0.44 ± 0.24, 0.35 ± 0.06, and 0.03 nmol/min, respectively).
• Ionic flow rates were tunable via membrane thickness and salt concentration.
• Precise ion delivery in minuscule doses (∼132 ± 9.7 nmol) was achieved through controlled heating or light application.
• The fabrication process enabled the design of complex devices like three-terminal-Ni-VO (3T-Ni-VO) systems.

Conclusions:

• Reconstructed vanadium pentoxide membranes can be used to create highly accurate iontronic devices.
• These devices offer tunable and precise control over ion delivery, mimicking biological ion channels.
• The simple fabrication method facilitates the development of advanced, multi-component iontronic systems.