서강대학교

초록

Iontronics based on asymmetric nanochannel networks membrane (NCNM) is realized through the self-assembly of nanoparticles and shows a broad range of control for ion transport using geometrical regulation and material selection. First, a bipolar ionic diode shows a high rectification degree and induces ion concentrations at the heterogeneous junction between anion and cation-selective NCNM, based on the accumulation effect under the forward potential bias. Using this phenomenon, the accumulation of mercury ions at the heterojunction is applied, and modeled numerically, which results in a ~100-fold signal amplification regardless of the initial concentration. Experimentally, the detection limit of mercury ion is 10 pM, which is ~10 times lower than the best detection limit realized so far in fluorescence-based sensors. Next, an ionic bipolar junction transistor(BJT) based on asymmetric nanochannel networks is proposed to regulate, switch, and amplify the ionic signal. The performance of ionic BJT can be adjusted by the proper design of the microchannel and selection of nanoparticles, which corresponds to the geometrical control and the doping concentration in a solid-state transistor. Through experimental and multiphysics numerical studies, the proposed ionic BJT can display all four solid-state transistor operation modes successfully: forward active, saturated, backward active, and cut-off. Experimentally, the device has a high amplification ratio of more than 11.48 times through the base voltage regulation.