Dynamic Nonlinear Behavior of Ionic Liquid-Based Reservoir Computing Devices

Abstract

Herein, a physical reservoir device that uses faradaic currents generated by redox reactions of metal ions in ionic liquids was developed. Synthetic time-series data consisting of randomly arranged binary number sequences ("1" and "0") were applied as isoscelestriangular voltage pulses with positive and negative voltage heights, respectively, and the effects of the faradaic current on short-term memory and parity-check task accuracies were verified. The current signal for the first half of the triangular voltage-pulse period, which contained a much higher faradaic current component compared to that of the second half of the triangular voltage-pulse period, enabled higher short-term memory task accuracy. Furthermore, when parity-check tasks were performed using a faradaic current generated by asymmetric triangular voltage-pulse levels of 1 and 0, the parity-check task accuracy was approximately eight times higher than that of the symmetric triangular voltage pulse in terms of the correlation coefficient between the output signal and target data. These results demonstrate the advantage of the faradaic current on both the short-term memory characteristics and nonlinear conversion capabilities and are expected to provide guidance for designing and controlling various physical reservoir devices that utilize electrochemical reactions.

Experimental and Theoretical Study of Solitary-like Wave Dynamics of Liquid Film Flows over a Vibrated Inclined Plane

“…Apart from a contribution of the fundamental knowledge, the results presented in this work may be used to better understand and further improve certain technological processes that rely on falling liquid films. Yet, the demonstrated immunity of the solitary-like waves to external vibration and their intriguing nonlinear dynamical behaviour will be of interest to researchers working on emergent technologies, where both solitary waves and fluidic systems play an important role [7,8,12,48,[59][60][61].…”

Liquid-Based Memory Devices for Next-Generation Computing

“…Based on these features, liquid-based memory devices have the potential to be emerging devices for sensing and synaptic applications. − Liquid-based devices provide the advantage of emulating synaptic characteristics because synaptic functions are realized by the movement of ions and neurotransmitters between the cerebrospinal fluid and neurons in the biological synapse. ,,, For instance, the ion concentration of the liquid-based memory devices was controlled by applying electrical stimuli to emulate the synaptic functions using ion reservoirs . The conductivity of the device was controlled by varying the concentration of the ions in the solution.…”

Solitary-like Wave Dynamics in Thin Liquid Films over a Vibrated Inclined Plane

“…Figure 3(b) shows the outcome of the parity check test that produces P C = 12.4 bits. In the literature on physical RC systems, the value of P C is usually slightly smaller than the value of M C and, typically, it reaches 2 bits [16,28,37,38]. The value of P C for algorithmic RC systems is larger than that of physical RC systems [36].…”

“…Although in the framework of LSM the analogy between a reservoir and a liquid was made rather at an abstract level [3], follow-up research works have demonstrated that physical liquids inherently possess all characteristics required for the creation of a reservoir [10][11][12][13][14][15][16]. There have also been theoretical proposals [17][18][19][20] of RC systems based on optical solitons [21].…”