Professor Zhen Zhang's research group at the State Key Laboratory of Bionic Interface Materials Science, University of Science and Technology of China, proposed and constructed a neuromorphic computing system based on a cascaded van der Waals heterostructure two-dimensional nanofluidic membrane, achieving light-driven electron-ion coupling to simulate neural signal transmission and neuromorphic visual information processing. The article was published as an open access Research Article in CCS Chemistry, the flagship journal of the Chinese Chemical Society.
Background information:
Biological nervous systems perceive light signals through dynamic ion migration, enabling efficient and multidimensional information processing. Inspired by this, neuromorphic devices capable of sensing light and adaptively regulating charge transport are becoming a research hotspot in artificial vision, brain-computer interfaces, and intelligent sensing. However, traditional devices, using electrons as charge carriers, only functionally mimic neural behavior and struggle to replicate the complex signal processing mediated by biological ions. Biomimetic nanofluidic technology provides a new platform for efficient ion signal transduction by precisely controlling ion migration at the nanoscale. However, traditional two-dimensional membrane structures typically consist of a single component with a thickness of only a few micrometers and contain only one active interface. This limits the efficiency of photogenerated charge separation and the ability to control ion migration paths, highlighting the crucial role of fine interface engineering in the design of novel neuromorphic devices.
Highlights of this article:
Biological nervous systems rely on the dynamic migration of ions within neural networks to achieve efficient information processing and adaptive regulation. Inspired by this, the research team constructed a cascaded GO-COF nanofluidic membrane, achieving photoelectric-ion coupling under light stimulation, providing a novel material platform for brain-like devices. This study is the first to integrate atomically precise van der Waals heterostructures into nanofluidic membranes, forming a "cascaded design." In this nanofluidic system, efficient ion-electron coupling is achieved. This "Lego-like" van der Waals structure creates highly tunable photoelectric-ion channels, overcoming the limitation of low interfacial activity in traditional heterojunctions, establishing a continuous, spatially controllable ion transport network, and significantly enhancing light-driven charge separation and atomic-level proton migration.
The results show that the cascaded GO-COFnanofluidic membrane exhibits significantly enhanced photoelectric-ion conversion capabilities under illumination. With the increase of the number of sulfonic acid groups in the COFs, the hydrophilicity of the membrane and the continuity of the proton transport channels are simultaneously improved, resulting in a continuous enhancement of photogenerated ion current and photoelectric potential.
Further analysis revealed that the cascaded heterostructure effectively promotes the spatial separation of photogenerated carriers, constructing an asymmetric built-in electric field within the membrane, thereby lowering the proton migration energy barrier and driving its directional and rapid transport. This synergistic mechanism not only significantly improves the efficiency of photodriven ion transport but also lays the physical foundation for subsequent neuromorphic ion signal modulation.
Building upon this foundation, we further expanded the application boundaries of two-dimensional nanofluidic membranes. While these materials have long received widespread attention in energy conversion, energy storage, and environmental technologies, their potential in neuromorphic computing remains to be explored. This work, for the first time, achieves photomodulated photoelectric-ion coupling based on two-dimensional nanofluidic membranes, endowing the device with synaptic plasticity and neural signal processing capabilities. This ion computing platform provides a new physical mechanism and material pathway for constructing efficient, scalable, and adaptive brain-like systems, demonstrating broad application prospects in intelligent information processing and brain-like visual devices.
Summary and Outlook:
This study outlines a novel strategy based on cascaded van der Waals heterojunctions for integrating optical and ion signal transduction, driving the development of neuromorphic computing systems toward higher energy efficiency, adaptability, and noise resistance, and highlighting the enormous potential of cascaded van der Waals heterojunctions in artificial intelligence vision and intelligent information processing.
This article was published as a Research Article in CCS Chemistry, the flagship journal of the Chinese Chemical Society. Professor Zhen Zhang of the University of Science and Technology of China (USTC) is the corresponding author, and Yifan Guo and Xi Wang, doctoral students of the School of Chemistry and Materials Science, USTC (Class of 2022), are the first authors. The State Key Laboratory of Bionic Interface Materials Science, Suzhou Advanced Research Institute, USTC, is the corresponding institution. This work was supported by the National Natural Science Foundation of China, the Startup Fund of Suzhou Advanced Research Institute, USTC, and the Suzhou Leading Talent Program. It also received support from the Center for Physical and Chemical Analysis, Suzhou Advanced Research Institute, USTC.
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About the journal: CCS Chemistry is the Chinese Chemical Society's flagship publication, established to serve as the preeminent international chemistry journal published in China. It is an English language journal that covers all areas of chemistry and the chemical sciences, including groundbreaking concepts, mechanisms, methods, materials, reactions, and applications. All articles are diamond open access, with no fees for authors or readers. More information can be found at https://www.chinesechemsoc.org/journal/ccschem .
About the Chinese Chemical Society: The Chinese Chemical Society (CCS) is an academic organization formed by Chinese chemists of their own accord with the purpose of uniting Chinese chemists at home and abroad to promote the development of chemistry in China. The CCS was founded during a meeting of preeminent chemists in Nanjing on August 4, 1932. It currently has more than 120,000 individual members and 184 organizational members. There are 7 Divisions covering the major areas of chemistry: physical, inorganic, organic, polymer, analytical, applied and chemical education, as well as 31 Commissions, including catalysis, computational chemistry, photochemistry, electrochemistry, organic solid chemistry, environmental chemistry, and many other sub-fields of the chemical sciences. The CCS also has 10 committees, including the Woman's Chemists Committee and Young Chemists Committee. More information can be found at https://www.chinesechemsoc.org/ .
