A team at Ulsan National Institute of Science and Technology has demonstrated a nanofluidic gate that switches ion current by precipitating salt inside a narrow channel, then dissolving it again with water. Connecting two gates in parallel demonstrated OR logic; a series connection demonstrated AND logic, the researchers report in Nature Communications.
In the test device, a bridge channel about 1 millimetre long, 1.5 micrometres wide and 120 nanometres high sat beside a gas-permeable polydimethylsiloxane (PDMS) membrane. Nitrogen purging drove pervaporation: water moved through the membrane, concentrating the electrolyte until salt crystallized and interrupted ion conduction. A pulse of deionized water dissolved the deposit and restored the conducting state.
At the 3 M potassium-chloride point in the Supplementary Information’s concentration sweep, the measured ON and OFF currents correspond to a conductance ratio above 100. Separate tests show switching with sodium chloride, calcium chloride and phosphate-buffered saline, but do not establish that each solution reaches the same ratio.
The supplementary setup changed between nitrogen and deionized-water inputs in about three seconds. That interval describes the fluid-control transition, not a transistor-like response-speed measurement. The prototype demonstrates iontronic logic in a micro/nanofluidic setup; operation in dense arrays with practical fluid control and electronic readout remains to be tested.
Illustrative image: a separate NIST-Cornell nanofluidic device, not the gate in this study. Credit: NIST, public domain via Wikimedia Commons.
Sources
- Ji, S., Seo, S. & Kim, T. “Tunable nanofluidic ion gating via in situ salt precipitation-dissolution.” Nature Communications, published September 25, 2026. Research paper and abstract.
- Official Supplementary Information (device dimensions, test conditions and input-switching setup).