Voltage-Induced Nanoprecipitation Creates Persistent Iontronic States in Solid-State Nanochannels
Year: 2026
Type: article
Abstract: The iontronic response of track-etched nanochannels typically exhibits ion current rectification in highly soluble electrolytes such as KCl. In contrast, measurements in moderate-solubility electrolytes such as KClO4 yield negative differential resistance and memory effects associated with voltage-induced precipitation−dissolution phenomena. Here, we show that this process not only enables reconfigurable iontronic functionality but also induces persistent structural modifications. After voltage-induced KClO4 precipitation, measurements in perchlorate-free KCl electrolyte no longer exhibit conventional rectification but instead display an S-shaped response characteristic of strong ion concentration polarization. This altered state persists over extended periods, indicating incomplete dissolution of trapped nanoprecipitates. Systematic studies as a function of electrolyte concentration and pH, rationalized by Poisson-Nernst-Planck simulations, show that attogram amounts of trapped solid suffice to generate a local ion-depleted zone and drive the channel into a polarization-dominated transport regime. As a result, the iontronic logic operation transitions from a two-input Exclusive-NOR (XNOR) gate in the pristine state to a single-input NOT gate controlled solely by pH. In addition, dynamic iontronic studies reveal enhanced capacitive hysteresis and modified impedance signatures. These findings demonstrate that precipitation induced by moderate-solubility electrolytes, together with the incomplete dissolution of trapped precipitates, can produce long-lasting, partially irreversible modifications in nanofluidic transport, leading to reconfigurable iontronic behavior and the loss of memristive properties, while potentially compromising device stability and reproducibility. This work highlights the importance of carefully considering precipitation phenomena when designing, operating, and interpreting the response of iontronic systems.
Source: ACS Nanoscience Au
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,500
OpenAlex ID: W7225813993