Circuit Descriptions of Switching and Storage Elements

Designing with Iontronic Logic Gates─From a Single Polyelectrolyte Diode to an Integrated Ionic Circuit

“…This residual concentration of ions stems from their slow diffusive transport relative to the temporal changes of the voltage, which resulted in an apparent negative differential resistance. ,,, The hysteresis grew with increased scanning rate [Figure S6] while shifting to negative voltages the transition point at which the diode was closed, and completely vanished in the steady-state response [Figure b]. This contrasts with solid-state diodes that exhibit a constant potential barrier (a typical value of V TR ≈ +0.7 V) to open the diode in high operation frequencies and without a hysteresis effect due to the significantly larger electron mobility and possible recombination of electrons and holes at the junction. , Increasing the voltage range beyond |1 V| introduced additional effects that further complicated the ionic diode’s response. Under reverse-biasing, water splitting into H+ and OH– generated excess mobile charge carriers that further elevated the I R once the electric field at the junction exceeded an order of MV/cm. , Based on the obtained current response, we evaluated the ability to reach these values as crossing a reverse breakdown voltage of V BR ≈ −1.4 V. In addition, under forward-biasing, generation of ionic depletion regions at the microchannel–polyelectrolyte interfaces due to ion-concentration polarization (ICP) was present as well, resulting in reduced conductance .…”

“…This contrasts with solid-state diodes that exhibit a constant potential barrier (a typical value of V TR ≈ +0.7 V) to open the diode in high operation frequencies and without a hysteresis effect due to the significantly larger electron mobility and possible recombination of electrons and holes at the junction. 5,44 Increasing the voltage range beyond |1 V| introduced additional effects that further complicated the ionic diode's response. Under reverse-biasing, water splitting into H+ and OH− generated excess mobile charge carriers that further elevated the I R once the electric field at the junction exceeded an order of MV/cm.…”

“…40−43 On the other hand, all of the mentioned differences are expected to have a major impact on the realization of a DLG using these diodes, and in particular on the integration of several DLGs into multistage circuits, which can further degrade its performance due to current leakages and parasitic resistances. To the best of our knowledge, the well-known behavior of solid-state DLG-based integrated circuits 44 has not been investigated in iontronic DLG-based fluidic circuits. Apart from the increased complexity involved in the physical description of ion transport relative to that of electrons, the challenge of a robust and reliable fabrication and integration of multiple ionic diodes onto a single chip has further made it difficult for implementation.…”

“…Its complexity stems from electrochemical electron–ion exchanges, the significantly lower mobility of ions compared to electrons, the variety of ionic species, the lack of ionic charge recombination, and fluid flow effects. , On the one hand, based on these unique properties, a rich variety of applications can be realized using ionic diodes, e.g., separation, gating, and sensing of ions or even power generation. − On the other hand, all of the mentioned differences are expected to have a major impact on the realization of a DLG using these diodes, and in particular on the integration of several DLGs into multistage circuits, which can further degrade its performance due to current leakages and parasitic resistances. To the best of our knowledge, the well-known behavior of solid-state DLG-based integrated circuits has not been investigated in iontronic DLG-based fluidic circuits. Apart from the increased complexity involved in the physical description of ion transport relative to that of electrons, the challenge of a robust and reliable fabrication and integration of multiple ionic diodes onto a single chip has further made it difficult for implementation.…”