TY - JOUR
T1 - Characterization of Information-Transmitting Materials Produced in Ionic Liquid-based Neuromorphic Electrochemical Devices for Physical Reservoir Computing
AU - Sato, Dan
AU - Shima, Hisashi
AU - Matsuo, Takuma
AU - Yonezawa, Masaharu
AU - Kinoshita, Kentaro
AU - Kobayashi, Masakazu
AU - Naitoh, Yasuhisa
AU - Akinaga, Hiroyuki
AU - Miyamoto, Shunsuke
AU - Nokami, Toshiki
AU - Itoh, Toshiyuki
N1 - Publisher Copyright:
© 2023 The Authors. Published by American Chemical Society.
PY - 2023/10/25
Y1 - 2023/10/25
N2 - Device implementation of reservoir computing, which is expected to enable high-performance data processing in simple neural networks at a low computational cost, is an important technology to accelerate the use of artificial intelligence in the real-world edge computing domain. Here, we propose an ionic liquid-based physical reservoir device (IL-PRD), in which copper cations dissolved in an IL induce diverse electrochemical current responses. The origin of the electrochemical current from the IL-PRD was investigated spectroscopically in detail. After operating the device under various operating conditions, X-ray photoelectron spectroscopy of the IL-PRD revealed that electrochemical reactions involving Cu, Cu2O, Cu(OH)2, CuSx, and H2O occur at the Pt electrode/IL interface. These products are considered information transmission materials in IL-PRD similar to neurotransmitters in biological neurons. By introducing the Faradaic current components due to the electrochemical reactions of these materials into the output signal of IL-PRD, we succeeded in improving the time-series data processing performance of the nonlinear autoregressive moving average task. In addition, the information processing efficiency in machine learning to classify electrocardiogram signal waveforms was successfully improved by using the output current from IL-PRD. Optimizing the electrochemical reaction products of IL-PRD is expected to advance data processing technology in society.
AB - Device implementation of reservoir computing, which is expected to enable high-performance data processing in simple neural networks at a low computational cost, is an important technology to accelerate the use of artificial intelligence in the real-world edge computing domain. Here, we propose an ionic liquid-based physical reservoir device (IL-PRD), in which copper cations dissolved in an IL induce diverse electrochemical current responses. The origin of the electrochemical current from the IL-PRD was investigated spectroscopically in detail. After operating the device under various operating conditions, X-ray photoelectron spectroscopy of the IL-PRD revealed that electrochemical reactions involving Cu, Cu2O, Cu(OH)2, CuSx, and H2O occur at the Pt electrode/IL interface. These products are considered information transmission materials in IL-PRD similar to neurotransmitters in biological neurons. By introducing the Faradaic current components due to the electrochemical reactions of these materials into the output signal of IL-PRD, we succeeded in improving the time-series data processing performance of the nonlinear autoregressive moving average task. In addition, the information processing efficiency in machine learning to classify electrocardiogram signal waveforms was successfully improved by using the output current from IL-PRD. Optimizing the electrochemical reaction products of IL-PRD is expected to advance data processing technology in society.
KW - electrochemical reaction
KW - faradaic current
KW - ionic liquid
KW - liquid/solid interface
KW - reservoir computing
UR - http://www.scopus.com/inward/record.url?scp=85175269366&partnerID=8YFLogxK
U2 - 10.1021/acsami.3c08638
DO - 10.1021/acsami.3c08638
M3 - Article
C2 - 37815984
AN - SCOPUS:85175269366
SN - 1944-8244
VL - 15
SP - 49712
EP - 49726
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 42
ER -