Organic electrochemical transistors have emerged as a solution for artificial synapses that mimic the neural functions of the brain structure,holding great potentials to break the bottleneck of von Neumann architectur...Organic electrochemical transistors have emerged as a solution for artificial synapses that mimic the neural functions of the brain structure,holding great potentials to break the bottleneck of von Neumann architectures.However,current artificial synapses rely primarily on electrical signals,and little attention has been paid to the vital role of neurotransmitter-mediated artificial synapses.Dopamine is a key neurotransmitter associated with emotion regulation and cognitive processes that needs to be monitored in real time to advance the development of disease diagnostics and neuroscience.To provide insights into the development of artificial synapses with neurotransmitter involvement,this review proposes three steps towards future biomimic and bioinspired neuromorphic systems.We first summarize OECT-based dopamine detection devices,and then review advances in neurotransmitter-mediated artificial synapses and resultant advanced neuromorphic systems.Finally,by exploring the challenges and opportunities related to such neuromorphic systems,we provide a perspective on the future development of biomimetic and bioinspired neuromorphic systems.展开更多
To present an advanced device scheme of high-performance optoelectronic synapses,herein,we demonstrated the electrically-and/or optically-drivable multifaceted synaptic capabilities on the 2D semiconductor channel-bas...To present an advanced device scheme of high-performance optoelectronic synapses,herein,we demonstrated the electrically-and/or optically-drivable multifaceted synaptic capabilities on the 2D semiconductor channel-based ferroelectric field-effect transistor(FeFET)architecture.The device was fabricated in the form of the MoS_(2)/PZT FeFET,and its synaptic weights were effectively controlled by dual stimuli(i.e.,both electrical and optical pulses simultaneously)as well as single stimuli(i.e.,either electrical or optical pulses alone).This could be attributed to the electrical pulse-tunable strong ferroelectric polarization in PbZrxTi_(1−x)O_(3)(PZT)as well as the polarization field-enhanced persistent photoconductivity effect in MoS_(2).Additionally,it was confirmed that the proposed device possesses substantial activity,achieving approximately 95%pattern recognition accuracy.The results substantiate the great potential of the 2D semiconductor channel-based FeFET device as a high-performance optoelectronic synaptic platform,marking a pivotal stride towards the realization of advanced neuromorphic computing systems.展开更多
Organic electrochemical transistors(OECTs)have emerged as one type of promising building block for neuromorphic systems owing to their capability of mimicking the morphology and functions of biological neurons and syn...Organic electrochemical transistors(OECTs)have emerged as one type of promising building block for neuromorphic systems owing to their capability of mimicking the morphology and functions of biological neurons and synapses.Currently,numerous kinds of OECTs have been developed,while self-healing performance has been neglected in most reported OECTs.In this work,the OECTs using self-healing polymer electrolytes as dielectric layers are proposed.Several important synaptic behaviors are simulated in the OECTs by doping the channel layers with ions from the electrolytes.Benefitting from the dynamic hydrogen bonds in the self-healing polymer electrolytes,the OECTs can successfully maintain their electrical performance and the ability of emulating synaptic behaviors after self-healing compared with the initial state.More significantly,the sublinear spatial summation function is demonstrated in the OECTs and their potential in flexible electronics is also validated.These results suggest that our devices are expected to be a vital component in the development of future wearable and bioimplantable neuromorphic systems.展开更多
Artificial synapses are essential building blocks for neuromorphic electronics.Here,solid polymer electrolyte-gated artificial synapses(EGASs)were fabricated using ITO fibers as channels,which possess an ultra-high se...Artificial synapses are essential building blocks for neuromorphic electronics.Here,solid polymer electrolyte-gated artificial synapses(EGASs)were fabricated using ITO fibers as channels,which possess an ultra-high sensitivity of 5 m V and a long-term memory time exceeding 3 min.Notably,digitally printed ITO-fiber arrays exhibit an ultra-high transmittance of approximately 99.67%.Biological synaptic plasticity,such as excitatory postsynaptic current,paired-pulse facilitation,spike frequency-dependent plasticity,and synaptic potentiation and depression,were successfully mimicked using the EGASs.Based on the synaptic properties of the EGASs,an artificial neural network was constructed to perform supervised learning using the Fashion-MNIST dataset,achieving high pattern recognition rate(82.39%)due to the linear and symmetric synaptic plasticity.This work provides insights into high-sensitivity artificial synapses for future neuromorphic computing.展开更多
Recently,artificial synapses involving an electrochemical reaction of Li-ion have been attributed to have remarkable synaptic properties.Three-terminal synaptic transistors utilizing Li-ion intercalation exhibits reli...Recently,artificial synapses involving an electrochemical reaction of Li-ion have been attributed to have remarkable synaptic properties.Three-terminal synaptic transistors utilizing Li-ion intercalation exhibits reliable synaptic characteristics by exploiting the advantage of nondistributed weight updates owing to stable ion migrations.However,the three-terminal configurations with large and complex structures impede the crossbar array implementation required for hardware neuromorphic systems.Meanwhile,achieving adequate synaptic performances through effective Li-ion intercalation in vertical two-terminal synaptic devices for array integration remains challenging.Here,two-terminal Au/LixCoO_(2)/Pt artificial synapses are proposed with the potential for practical implementation of hardware neural networks.The Au/LixCoO_(2)/Pt devices demonstrated extraordinary neuromorphic behaviors based on a progressive dearth of Li in LixCoO_(2)films.The intercalation and deintercalation of Li-ion inside the films are precisely controlled over the weight control spike,resulting in improved weight control functionality.Various types of synaptic plasticity were imitated and assessed in terms of key factors such as nonlinearity,symmetricity,and dynamic range.Notably,the LixCoO_(2)-based neuromorphic system outperformed three-terminal synaptic transistors in simulations of convolutional neural networks and multilayer perceptrons due to the high linearity and low programming error.These impressive performances suggest the vertical two-terminal Au/LixCoO_(2)/Pt artificial synapses as promising candidates for hardware neural networks.展开更多
Neuromorphic devices inspired by the human brain have attracted significant attention because of their excellent ability for cognitive and parallel computing.This study presents ZnO-based artificial synapses with pept...Neuromorphic devices inspired by the human brain have attracted significant attention because of their excellent ability for cognitive and parallel computing.This study presents ZnO-based artificial synapses with peptide insulators for the electrical emulation of biological synapses.We demonstrated the dynamic responses of the device under various environmental conditions.The proton-conducting property of the tyrosine-rich peptide enables time-dependent responses under ambient conditions such that various aspects of synaptic behaviors are emulated by the devices.The transition from short-term memory to longterm memory is achieved via electrochemical doping of ZnO by protons.Furthermore,we demonstrate an image classification simulation using a multi-layer perceptron model to evaluate the potential of the device for use in neuromorphic computing.The neural network based on our device achieved a recognition accuracy of 87.47% for the MNIST handwritten digit images.This work proposes a novel device platform inspired by biosystems for brain-mimetic hardware systems.展开更多
The rapid development of neuromorphic computing has led to widespread investigation of artificial synapses.These synapses can perform parallel in-memory computing functions while transmitting signals,enabling low-ener...The rapid development of neuromorphic computing has led to widespread investigation of artificial synapses.These synapses can perform parallel in-memory computing functions while transmitting signals,enabling low-energy and fast artificial intelligence.Robots are the most ideal endpoint for the application of artificial intelligence.In the human nervous system,there are different types of synapses for sensory input,allowing for signal preprocessing at the receiving end.Therefore,the development of anthropomorphic intelligent robots requires not only an artificial intelligence system as the brain but also the combination of multimodal artificial synapses for multisensory sensing,including visual,tactile,olfactory,auditory,and taste.This article reviews the working mechanisms of artificial synapses with different stimulation and response modalities,and presents their use in various neuromorphic tasks.We aim to provide researchers in this frontier field with a comprehensive understanding of multimodal artificial synapses.展开更多
Organic electrochemical transistors(OECTs)have garnered significant attention as artificial synapses due to their ability to emulate synaptic functionalities.While previous research has predominantly focused on modula...Organic electrochemical transistors(OECTs)have garnered significant attention as artificial synapses due to their ability to emulate synaptic functionalities.While previous research has predominantly focused on modulating the physical properties of the channel materials to enhance synaptic performance,the role of ion dynamics in influencing device characteristics remains underexplored.Effective regulation of ion dynamics is crucial for improving state retention and achieving long-term plasticity(LTP)in these devices.In this study,we propose a strategy to modulate the interactions between polymer semiconductors and ions in solid-electrolyte-based artificial synapses.Our findings indicate that the interplay between semiconductors and doping counterions significantly influences ion transport dynamics,thereby affecting the electrochemical doping and dedoping pro-cesses in OECTs.Notably,by suppressing the dedoping process,we achieved enhanced synaptic performances,with devices retaining 64%of the peak current after a retention time of 1000 s.Through the judicious selection of anions and optimization of their interactions with polymer semiconductors,we effectively controlled the dedoping process in OECTs,leading to improved state retention.These insights provide a novel perspective on tuning ion-polymer semiconductor interactions for the development of high-performance synaptic devices,advancing neuromorphic computing applications.展开更多
Optoelectronic memristors possess capabilities of data storage and mimicking human visual perception.They hold great promise in neuromorphic visual systems(NVs).This study introduces the amorphous wide-bandgap Ga_(2)O...Optoelectronic memristors possess capabilities of data storage and mimicking human visual perception.They hold great promise in neuromorphic visual systems(NVs).This study introduces the amorphous wide-bandgap Ga_(2)O_(3)photoelectric synaptic memristor,which achieves 3-bit data storage through the adjustment of current compliance(Icc)and the utilization of variable ultraviolet(UV-254 nm)light intensities.The“AND”and“OR”logic gates in memristor-aided logic(MAGIC)are implemented by utilizing voltage polarity and UV light as input signals.The device also exhibits highly stable synaptic characteristics such as paired-pulse facilitation(PPF),spike-intensity dependent plasticity(SIDP),spike-number dependent plasticity(SNDP),spike-time dependent plasticity(STDP),spike-frequency dependent plasticity(SFDP)and the learning experience behavior.Finally,when integrated into an artificial neural network(ANN),the Ag/Ga_(2)O_(3)/Pt memristive device mimicked optical pulse potentiation and electrical pulse depression with high pattern accuracy(90.7%).The single memristive cells with multifunctional features are promising candidates for optoelectronic memory storage,neuromorphic computing,and artificial visual perception applications.展开更多
The emulation of biological synapses with learning and memory functions and versatile plasticity is significantly promising for neuromorphic computing systems.Here,a robust and continuously adjustable mechanoplastic s...The emulation of biological synapses with learning and memory functions and versatile plasticity is significantly promising for neuromorphic computing systems.Here,a robust and continuously adjustable mechanoplastic semifloating-gate transistor is demonstrated based on an integrated graphene/hexagonal boron nitride/tungsten diselenide van der Waals heterostructure and a triboelectric nanogenerator(TENG).The working states(p-n junction or n;-n junction)can be manipulated and switched under the sophisticated modulation of triboelectric potential derived from mechanical actions,which is attributed to carriers trapping and detrapping in the graphene layer.Furthermore,a reconfigurable artificial synapse is constructed based on such mechanoplastic transistor that can simulate typical synaptic plasticity and implement dynamic control correlations in each response mode by further designing the amplitude and duration.The artificial synapse can work with ultra-low energy consumption at 74.2 f J per synaptic event and the extended synaptic weights.Under the synergetic effect of the semifloating gate,the synaptic device can enable successive mechanical facilitation/depression,short-/long-term plasticity and learning-experience behavior,exhibiting the mechanical behavior derived synaptic plasticity.Such reconfigurable and mechanoplastic features provide an insight into the applications of energyefficient and real-time interactive neuromodulation in the future artificial intelligent system beyond von Neumann architecture.展开更多
Gradient heterostructure is one of fundamental interfaces and provides an effective platform to achieve gradually changed properties in mechanics,optics,and electronics.Among different types of heterostructures,the gr...Gradient heterostructure is one of fundamental interfaces and provides an effective platform to achieve gradually changed properties in mechanics,optics,and electronics.Among different types of heterostructures,the gradient one may provide multiple resistive states and immobilized conductive fila-ments,offering great prospect for fabricating memristors with both high neuromorphic computation capability and repeatability.Here,we invent a memristor based on a homologous gradient heterostructure(HGHS),compris-ing a conductive transition metal dichalcogenide and an insulating homolo-gous metal oxide.Memristor made of Ta–TaS_(x)O_(y)–TaS 2 HGHS exhibits continuous potentiation/depression behavior and repeatable forward/backward scanning in the read-voltage range,which are dominated by multi-ple resistive states and immobilized conductive filaments in HGHS,respec-tively.Moreover,the continuous potentiation/depression behavior makes the memristor serve as a synapse,featuring broad-frequency response(10^(-1)–10^(5) Hz,covering 106 frequency range)and multiple-mode learning(enhanced,depressed,and random-level modes)based on its natural and moti-vated forgetting behaviors.Such HGHS-based memristor also shows good unifor-mity for 5?7 device arrays.Our work paves a way to achieve high-performance integrated memristors for future artificial neuromorphic computation.展开更多
State number,operation power,dynamic range and conductance weight update linearity are key synaptic device performance metrics for high-accuracy and low-power-consumption neuromorphic com-puting in hardware.However,hi...State number,operation power,dynamic range and conductance weight update linearity are key synaptic device performance metrics for high-accuracy and low-power-consumption neuromorphic com-puting in hardware.However,high linearity and low power consump-tion couldn’t be simultaneously achieved by most of the reported synaptic devices,which limits the performance of the hardware.This work demonstrates van der Waals(vdW)stacked ferroelectric field-effect transistors(FeFET)with single-crystalline ferroelectric nanoflakes.Ferroelectrics are of fine vdW interface and partial polar-ization switching of multi-domains under electric field pulses,which makes the FeFETs exhibit multi-state memory characteristics and ex-cellent synaptic plasticity.They also exhibit a desired linear conduc-tance weight update with 128 conductance states,a sufficiently high dynamic range of G_(max)/G_(min)>120,and a low power consumption of 10 fJ/spike using identical pulses.Based on such an all-round device,a two-layer artificial neural network was built to conduct Modified Na-tional Institute of Standards and Technology(MNIST)digital num-bers and electrocardiogram(ECG)pattern-recognition simulations,with the high accuracies reaching 97.6%and 92.4%,respectively.The remarkable performance demonstrates that vdW-FeFET is of obvious advantages in high-precision neuromorphic computing applications.展开更多
Ag/Ta_(2)O_(5)/CuO/Pt memristive devices with Ag point contacts at the interface exhibit forming-free and partial volatile analog resistive switching properties.Versatile synaptic functions,like the short-term plastic...Ag/Ta_(2)O_(5)/CuO/Pt memristive devices with Ag point contacts at the interface exhibit forming-free and partial volatile analog resistive switching properties.Versatile synaptic functions,like the short-term plasticity,the long-term potentiation and the paired-pulse facilitation,are emulated with these devices.The Ag point contacts in the Ta_(2)O_(5)layer are verified through transmission electron microscope(TEM)and X-ray photoelectron spectroscope(XPS).The Ag point contacts at the interface endow the device the transition from the electrochemical metallization mode to the valence change mode,and the analog resistive switching behavior and neuromorphic functions.This interface engineering of introducing point contacts at the interface provides a way for the development of neuromorphic devices with low power consumption.展开更多
Due to its non-invasive nature,ultrasound has been widely used for neuromodulation in biological systems,where its application influences the synaptic weights and the process of neurotransmitter delivery.However,such ...Due to its non-invasive nature,ultrasound has been widely used for neuromodulation in biological systems,where its application influences the synaptic weights and the process of neurotransmitter delivery.However,such modulation has not been emulated in physical devices.Memristors are ideal electrical components for artificial synapses,but up till now they are hardly reported to respond to ultrasound signals.Here we design and fabricate a HfOx-based memristor on 64Y-X LiNbO_(3) single crystal substrate,and successfully realize artificial synapses modulation by shear-horizontal surface acoustic wave(SH-SAW).It is a prominent short-term resistance modulation,where ultrasound has been shown to cause resistance drop for various resistance states,which could fully recover after the ultrasound is shut off.The physical mechanism illustrates that ultrasound induced polarization potential in the HfOx dielectric layer acts on the Schottky barrier,leading to the resistance drop.The emulation of neuron firing frequency modulation through ultrasound signals is demonstrated.Moreover,the joint application of ultrasound and electric voltage yields fruitful functionalities,such as the enhancement of resistance window and synaptic plasticity through ultrasound application.All these promising results provide a new strategy for artificial synapses modulation,and also further advance neuromorphic devices toward system applications.展开更多
As key components of artificial afferent nervous systems,synaptic devices can mimic the physiological synaptic behaviors,which have attracted extensive attentions.Here,a flexible tribotronic artificial synapse(TAS)wit...As key components of artificial afferent nervous systems,synaptic devices can mimic the physiological synaptic behaviors,which have attracted extensive attentions.Here,a flexible tribotronic artificial synapse(TAS)with bioinspired neurosensory behavior is developed.The triboelectric potential generated by the external contact electrification is used as the ion-gel-gate voltage of the organic thin film transistor,which can tune the carriers transport through the migration/accumulation of ions.The TAS successfully demonstrates a series of synaptic behaviors by external stimuli,such as excitatory postsynaptic current,paired-pulse facilitation,and the hierarchical memory process from sensory memory to short-term memory and long-term memory.Moreover,the synaptic behaviors remained stable under the strain condition with a bending radius of 20 mm,and the TAS still exhibits excellent durability after 1000 bending cycles.Finally,Pavlovian conditioning has been successfully mimicked by applying force and vibration as food and bell,respectively.This work demonstrates a bioinspired flexible artificial synapse that will help to facilitate the development of artificial afferent nervous systems,which is great significance to the practical application of artificial limbs,robotics,and bionics in future.展开更多
Memtransistor,a multi-terminal device that combines both the characteristics of a memristor and a transistor,has been intensively studied in two-dimensional layered materials(2 DLM),which show potential for applicatio...Memtransistor,a multi-terminal device that combines both the characteristics of a memristor and a transistor,has been intensively studied in two-dimensional layered materials(2 DLM),which show potential for applications in such as neuromorphic computation.However,while often based on the migration of ions or atomic defects in the conduction channels,performances of memtransistors suffer from the poor reliability and tunability.Furthermore,those known 2 DLM-based memtransistors are mostly constructed in a lateral manner,which hinders the further increasing of the transistor densities per area.Until now,fabricating non-atomic-diffusion based memtransistors with vertical structure remains challenging.Here,we demonstrate a vertically-integrated ferroelectric memristor by hetero-integrating the 2 D ferroelectric materials CuInP_(2)S_(6)(CIPS)into a graphite/CuInP_(2)S_(6)/MoS_(2)vertical heterostructure.Memristive behaviour and multi-level resistance states were realized.Essential synaptic behaviours including excitatory postsynaptic current,paired-pulse-facilitation,and spike-amplitude-dependent plasticity are successfully mimicked.Moreover,by applying a gate potential,the memristive behaviour and synaptic features can be effectively gate tuned.Our findings pave the way for the realization of novel gate-tunable ferroelectric synaptic devices with the capability to perform complex neural functions.展开更多
Phase-change material(PCM)is generating widespread interest as a new candidate for artificial synapses in bioinspired computer systems.However,the amorphization process of PCM devices tends to be abrupt,unlike continu...Phase-change material(PCM)is generating widespread interest as a new candidate for artificial synapses in bioinspired computer systems.However,the amorphization process of PCM devices tends to be abrupt,unlike continuous synaptic depression.The relatively large power consumption and poor analog behavior of PCM devices greatly limit their applications.Here,we fabricate a GeTe/Sb2Te3 superlattice-like PCM device which allows a progressive RESET process.Our devices feature low-power consumption operation and potential high-density integration,which can effectively simulate biological synaptic characteristics.The programming energy can be further reduced by properly selecting the resistance range and operating method.The fabricated devices are implemented in both artificial neural networks(ANN)and convolutional neural network(CNN)simulations,demonstrating high accuracy in brain-like pattern recognition.展开更多
Artificial synapse inspired by the biological brain has great potential in the field of neuromorphic computing and artificial intelligence.The memristor is an ideal artificial synaptic device with fast operation and g...Artificial synapse inspired by the biological brain has great potential in the field of neuromorphic computing and artificial intelligence.The memristor is an ideal artificial synaptic device with fast operation and good tolerance.Here,we have prepared a memristor device with Au/CsPbBr_(3)/ITO structure.The memristor device exhibits resistance switching behavior,the high and low resistance states no obvious decline after 400 switching times.The memristor device is stimulated by voltage pulses to simulate biological synaptic plasticity,such as long-term potentiation,long-term depression,pair-pulse facilitation,short-term depression,and short-term potentiation.The transformation from short-term memory to long-term memory is achieved by changing the stimulation frequency.In addition,a convolutional neural network was constructed to train/recognize MNIST handwritten data sets;a distinguished recognition accuracy of~96.7%on the digital image was obtained in 100 epochs,which is more accurate than other memristor-based neural networks.These results show that the memristor device based on CsPbBr3 has immense potential in the neuromorphic computing system.展开更多
A flexible organic artificial synapse(OAS)for tunable time-frequency signal processing was fabricated using a tri-blend film that had been fabricated using a one-step solution method.When combined with a chitosan film...A flexible organic artificial synapse(OAS)for tunable time-frequency signal processing was fabricated using a tri-blend film that had been fabricated using a one-step solution method.When combined with a chitosan film,this OAS can achieve an ultrashort-term retention time of only 49 ms for instant electricalcomputing applications;this is the shortest retention time yet achieved by a two-terminal artificial synapse.An array of these flexible OASs can withstand a high bending strain of 5%for 10^(4) cycles;this deformation endurance is a new record.The OAS was also sensitive to the number and frequency of electrical inputs;a tunable cut-off frequency enables dynamic filtering for use in image detail enhancement.This work provides a new resource for development of future neuromorphic computing devices。展开更多
The synapse of human brain neurons is not only the transmission channel of information,but also the basic unit of human brain learning and information storing.The artificial synapse is constructed based on the Sr_(0.9...The synapse of human brain neurons is not only the transmission channel of information,but also the basic unit of human brain learning and information storing.The artificial synapse is constructed based on the Sr_(0.97)Ba_(0.03)TiO_(3-x)(SBT)memristor,which realizes the short-term and long-term plasticity of the synapse.The experiential learning and non-associative learning behavior in accordance with human cognitive rules are realized by using the SBT-memristor-based synapse.The process of synaptic habituation and sensitization is analyzed.This study provides insightful guidance for realization of artificial synapse and the development of artificial neural network.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62074163)Beijing Natural Science Foundation(Grant No.JQ24030).
文摘Organic electrochemical transistors have emerged as a solution for artificial synapses that mimic the neural functions of the brain structure,holding great potentials to break the bottleneck of von Neumann architectures.However,current artificial synapses rely primarily on electrical signals,and little attention has been paid to the vital role of neurotransmitter-mediated artificial synapses.Dopamine is a key neurotransmitter associated with emotion regulation and cognitive processes that needs to be monitored in real time to advance the development of disease diagnostics and neuroscience.To provide insights into the development of artificial synapses with neurotransmitter involvement,this review proposes three steps towards future biomimic and bioinspired neuromorphic systems.We first summarize OECT-based dopamine detection devices,and then review advances in neurotransmitter-mediated artificial synapses and resultant advanced neuromorphic systems.Finally,by exploring the challenges and opportunities related to such neuromorphic systems,we provide a perspective on the future development of biomimetic and bioinspired neuromorphic systems.
基金supported by the National Research Foundation(NRF)of Korea through the Basic Science Research Programs(Nos.2019R1A2C1085448,2023R1A2C1005421,RS-2024-00356939)funded by the Korean Government.
文摘To present an advanced device scheme of high-performance optoelectronic synapses,herein,we demonstrated the electrically-and/or optically-drivable multifaceted synaptic capabilities on the 2D semiconductor channel-based ferroelectric field-effect transistor(FeFET)architecture.The device was fabricated in the form of the MoS_(2)/PZT FeFET,and its synaptic weights were effectively controlled by dual stimuli(i.e.,both electrical and optical pulses simultaneously)as well as single stimuli(i.e.,either electrical or optical pulses alone).This could be attributed to the electrical pulse-tunable strong ferroelectric polarization in PbZrxTi_(1−x)O_(3)(PZT)as well as the polarization field-enhanced persistent photoconductivity effect in MoS_(2).Additionally,it was confirmed that the proposed device possesses substantial activity,achieving approximately 95%pattern recognition accuracy.The results substantiate the great potential of the 2D semiconductor channel-based FeFET device as a high-performance optoelectronic synaptic platform,marking a pivotal stride towards the realization of advanced neuromorphic computing systems.
基金supported by the National Key Research and Development Program of China(No.2021YFA1101303)the National Natural Science Foundation of China(Nos.62074111,62088101)+2 种基金the Science&Technology Foundation of Shanghai(No.20JC1415600)Shanghai Municipal Science and Technology Major Project(No.2021SHZDZX0100)the Innovation Program of Shanghai Municipal Education Commission(No.2021-01-07-0007-E00096)。
文摘Organic electrochemical transistors(OECTs)have emerged as one type of promising building block for neuromorphic systems owing to their capability of mimicking the morphology and functions of biological neurons and synapses.Currently,numerous kinds of OECTs have been developed,while self-healing performance has been neglected in most reported OECTs.In this work,the OECTs using self-healing polymer electrolytes as dielectric layers are proposed.Several important synaptic behaviors are simulated in the OECTs by doping the channel layers with ions from the electrolytes.Benefitting from the dynamic hydrogen bonds in the self-healing polymer electrolytes,the OECTs can successfully maintain their electrical performance and the ability of emulating synaptic behaviors after self-healing compared with the initial state.More significantly,the sublinear spatial summation function is demonstrated in the OECTs and their potential in flexible electronics is also validated.These results suggest that our devices are expected to be a vital component in the development of future wearable and bioimplantable neuromorphic systems.
基金supported by the National Science Fund for Distinguished Young Scholars of China(No.T2125005)the National Key R&D Program of China(Nos.2022YFE0198200,2022YFA1204500,2022YFA1204504)+3 种基金the Shenzhen Science and Technology Project(No.JCYJ20210324121002008)the Natural Science Foundation of Tianjin(Nos.22JCYBJC01290,23JCQNJC01440)the Key Project of Nature Science Foundation of Tianjin(No.22JCZDJC00120)the Fundamental Research Funds for the Central Universities,Nankai University(Nos.BEG124901,BEG124401)。
文摘Artificial synapses are essential building blocks for neuromorphic electronics.Here,solid polymer electrolyte-gated artificial synapses(EGASs)were fabricated using ITO fibers as channels,which possess an ultra-high sensitivity of 5 m V and a long-term memory time exceeding 3 min.Notably,digitally printed ITO-fiber arrays exhibit an ultra-high transmittance of approximately 99.67%.Biological synaptic plasticity,such as excitatory postsynaptic current,paired-pulse facilitation,spike frequency-dependent plasticity,and synaptic potentiation and depression,were successfully mimicked using the EGASs.Based on the synaptic properties of the EGASs,an artificial neural network was constructed to perform supervised learning using the Fashion-MNIST dataset,achieving high pattern recognition rate(82.39%)due to the linear and symmetric synaptic plasticity.This work provides insights into high-sensitivity artificial synapses for future neuromorphic computing.
基金financially supported by National R&D Program(2018M3D1A1058793,2021M3H4A3A02086430)through NRF(National Research Foundation of Korea)funded by the Ministry of Science and ICTsupported by SAIT,Samsung Electronics Co.,Ltd。
文摘Recently,artificial synapses involving an electrochemical reaction of Li-ion have been attributed to have remarkable synaptic properties.Three-terminal synaptic transistors utilizing Li-ion intercalation exhibits reliable synaptic characteristics by exploiting the advantage of nondistributed weight updates owing to stable ion migrations.However,the three-terminal configurations with large and complex structures impede the crossbar array implementation required for hardware neuromorphic systems.Meanwhile,achieving adequate synaptic performances through effective Li-ion intercalation in vertical two-terminal synaptic devices for array integration remains challenging.Here,two-terminal Au/LixCoO_(2)/Pt artificial synapses are proposed with the potential for practical implementation of hardware neural networks.The Au/LixCoO_(2)/Pt devices demonstrated extraordinary neuromorphic behaviors based on a progressive dearth of Li in LixCoO_(2)films.The intercalation and deintercalation of Li-ion inside the films are precisely controlled over the weight control spike,resulting in improved weight control functionality.Various types of synaptic plasticity were imitated and assessed in terms of key factors such as nonlinearity,symmetricity,and dynamic range.Notably,the LixCoO_(2)-based neuromorphic system outperformed three-terminal synaptic transistors in simulations of convolutional neural networks and multilayer perceptrons due to the high linearity and low programming error.These impressive performances suggest the vertical two-terminal Au/LixCoO_(2)/Pt artificial synapses as promising candidates for hardware neural networks.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2020R1A2C2004864)。
文摘Neuromorphic devices inspired by the human brain have attracted significant attention because of their excellent ability for cognitive and parallel computing.This study presents ZnO-based artificial synapses with peptide insulators for the electrical emulation of biological synapses.We demonstrated the dynamic responses of the device under various environmental conditions.The proton-conducting property of the tyrosine-rich peptide enables time-dependent responses under ambient conditions such that various aspects of synaptic behaviors are emulated by the devices.The transition from short-term memory to longterm memory is achieved via electrochemical doping of ZnO by protons.Furthermore,we demonstrate an image classification simulation using a multi-layer perceptron model to evaluate the potential of the device for use in neuromorphic computing.The neural network based on our device achieved a recognition accuracy of 87.47% for the MNIST handwritten digit images.This work proposes a novel device platform inspired by biosystems for brain-mimetic hardware systems.
基金supported by the Science and Technology Commission of Shanghai Municipality(grant no.21DZ1100500)the Shanghai Municipal Science and Technology Major Project,the Shanghai Frontiers Science Center Program(2021-2025 No.20)the Shanghai Sailing Program(23YF1429500).
文摘The rapid development of neuromorphic computing has led to widespread investigation of artificial synapses.These synapses can perform parallel in-memory computing functions while transmitting signals,enabling low-energy and fast artificial intelligence.Robots are the most ideal endpoint for the application of artificial intelligence.In the human nervous system,there are different types of synapses for sensory input,allowing for signal preprocessing at the receiving end.Therefore,the development of anthropomorphic intelligent robots requires not only an artificial intelligence system as the brain but also the combination of multimodal artificial synapses for multisensory sensing,including visual,tactile,olfactory,auditory,and taste.This article reviews the working mechanisms of artificial synapses with different stimulation and response modalities,and presents their use in various neuromorphic tasks.We aim to provide researchers in this frontier field with a comprehensive understanding of multimodal artificial synapses.
基金supported by the Hunan Provincial Natural Science Foundation of China(2022JJ40547 and 2024JJ5031)the University of Defense Technology Research Project(ZK22-15)the National Natural Science Foundation of China(61871060 and 51201022).
文摘Organic electrochemical transistors(OECTs)have garnered significant attention as artificial synapses due to their ability to emulate synaptic functionalities.While previous research has predominantly focused on modulating the physical properties of the channel materials to enhance synaptic performance,the role of ion dynamics in influencing device characteristics remains underexplored.Effective regulation of ion dynamics is crucial for improving state retention and achieving long-term plasticity(LTP)in these devices.In this study,we propose a strategy to modulate the interactions between polymer semiconductors and ions in solid-electrolyte-based artificial synapses.Our findings indicate that the interplay between semiconductors and doping counterions significantly influences ion transport dynamics,thereby affecting the electrochemical doping and dedoping pro-cesses in OECTs.Notably,by suppressing the dedoping process,we achieved enhanced synaptic performances,with devices retaining 64%of the peak current after a retention time of 1000 s.Through the judicious selection of anions and optimization of their interactions with polymer semiconductors,we effectively controlled the dedoping process in OECTs,leading to improved state retention.These insights provide a novel perspective on tuning ion-polymer semiconductor interactions for the development of high-performance synaptic devices,advancing neuromorphic computing applications.
基金supported by National Key Research and Development Program of China(Grant 2021YFA0715600,2021YFA0717700,2018YFB2202900)the National Natural Science Foundation of China(52192610,62274127,62374128,62304167)+7 种基金2023 Qinchuangyuan Construction Two Chain Integration Special Project(23LLRH0043)Key Research and Development Program of Shaanxi Province(Grant 2024GXYBXM-512)CAS Project for Young Scientists in Basic Research(YSBR-113)the open fund of State Key Laboratory of Infrared Physics(SITP-NLIST-ZD-2023-03)the open research fund of Songshan Lake Materials Laboratory(2023SLABFN02)the Wuhu and Xidian University special fund for industryuniversity-research cooperation(XWYCXY-012021004)China Postdoctoral Science Foundation(2023TQ0255)the Fundamental Research Funds for the Central Universities and the Innovation Fund of Xidian University.
文摘Optoelectronic memristors possess capabilities of data storage and mimicking human visual perception.They hold great promise in neuromorphic visual systems(NVs).This study introduces the amorphous wide-bandgap Ga_(2)O_(3)photoelectric synaptic memristor,which achieves 3-bit data storage through the adjustment of current compliance(Icc)and the utilization of variable ultraviolet(UV-254 nm)light intensities.The“AND”and“OR”logic gates in memristor-aided logic(MAGIC)are implemented by utilizing voltage polarity and UV light as input signals.The device also exhibits highly stable synaptic characteristics such as paired-pulse facilitation(PPF),spike-intensity dependent plasticity(SIDP),spike-number dependent plasticity(SNDP),spike-time dependent plasticity(STDP),spike-frequency dependent plasticity(SFDP)and the learning experience behavior.Finally,when integrated into an artificial neural network(ANN),the Ag/Ga_(2)O_(3)/Pt memristive device mimicked optical pulse potentiation and electrical pulse depression with high pattern accuracy(90.7%).The single memristive cells with multifunctional features are promising candidates for optoelectronic memory storage,neuromorphic computing,and artificial visual perception applications.
基金supported by the National Natural Science Foundation of China(51872031,52073032,and 61904013)the Fundamental Research Funds for the Central Universities。
文摘The emulation of biological synapses with learning and memory functions and versatile plasticity is significantly promising for neuromorphic computing systems.Here,a robust and continuously adjustable mechanoplastic semifloating-gate transistor is demonstrated based on an integrated graphene/hexagonal boron nitride/tungsten diselenide van der Waals heterostructure and a triboelectric nanogenerator(TENG).The working states(p-n junction or n;-n junction)can be manipulated and switched under the sophisticated modulation of triboelectric potential derived from mechanical actions,which is attributed to carriers trapping and detrapping in the graphene layer.Furthermore,a reconfigurable artificial synapse is constructed based on such mechanoplastic transistor that can simulate typical synaptic plasticity and implement dynamic control correlations in each response mode by further designing the amplitude and duration.The artificial synapse can work with ultra-low energy consumption at 74.2 f J per synaptic event and the extended synaptic weights.Under the synergetic effect of the semifloating gate,the synaptic device can enable successive mechanical facilitation/depression,short-/long-term plasticity and learning-experience behavior,exhibiting the mechanical behavior derived synaptic plasticity.Such reconfigurable and mechanoplastic features provide an insight into the applications of energyefficient and real-time interactive neuromodulation in the future artificial intelligent system beyond von Neumann architecture.
基金We thank the financial support from the National Science Fund for Distinguished Young Scholars(No.52125309)the National Natural Science Foundation of China(Nos.51991343,52188101,51920105002,and 51991340)+1 种基金Guang-dong Innovative and Entrepreneurial Research Team Pro-gram(No.2017ZT07C341)the Shenzhen Basic Research Program(Nos.JCYJ20200109144616617 and JCYJ20200109144620815)。
文摘Gradient heterostructure is one of fundamental interfaces and provides an effective platform to achieve gradually changed properties in mechanics,optics,and electronics.Among different types of heterostructures,the gradient one may provide multiple resistive states and immobilized conductive fila-ments,offering great prospect for fabricating memristors with both high neuromorphic computation capability and repeatability.Here,we invent a memristor based on a homologous gradient heterostructure(HGHS),compris-ing a conductive transition metal dichalcogenide and an insulating homolo-gous metal oxide.Memristor made of Ta–TaS_(x)O_(y)–TaS 2 HGHS exhibits continuous potentiation/depression behavior and repeatable forward/backward scanning in the read-voltage range,which are dominated by multi-ple resistive states and immobilized conductive filaments in HGHS,respec-tively.Moreover,the continuous potentiation/depression behavior makes the memristor serve as a synapse,featuring broad-frequency response(10^(-1)–10^(5) Hz,covering 106 frequency range)and multiple-mode learning(enhanced,depressed,and random-level modes)based on its natural and moti-vated forgetting behaviors.Such HGHS-based memristor also shows good unifor-mity for 5?7 device arrays.Our work paves a way to achieve high-performance integrated memristors for future artificial neuromorphic computation.
文摘State number,operation power,dynamic range and conductance weight update linearity are key synaptic device performance metrics for high-accuracy and low-power-consumption neuromorphic com-puting in hardware.However,high linearity and low power consump-tion couldn’t be simultaneously achieved by most of the reported synaptic devices,which limits the performance of the hardware.This work demonstrates van der Waals(vdW)stacked ferroelectric field-effect transistors(FeFET)with single-crystalline ferroelectric nanoflakes.Ferroelectrics are of fine vdW interface and partial polar-ization switching of multi-domains under electric field pulses,which makes the FeFETs exhibit multi-state memory characteristics and ex-cellent synaptic plasticity.They also exhibit a desired linear conduc-tance weight update with 128 conductance states,a sufficiently high dynamic range of G_(max)/G_(min)>120,and a low power consumption of 10 fJ/spike using identical pulses.Based on such an all-round device,a two-layer artificial neural network was built to conduct Modified Na-tional Institute of Standards and Technology(MNIST)digital num-bers and electrocardiogram(ECG)pattern-recognition simulations,with the high accuracies reaching 97.6%and 92.4%,respectively.The remarkable performance demonstrates that vdW-FeFET is of obvious advantages in high-precision neuromorphic computing applications.
基金This work is supported by the National Natural Science Foundation of China(Grant No.51772112,U1832116 and 51372094)Fundamental Research Funds for the Central Universities(HUST:2016YXZD058).
文摘Ag/Ta_(2)O_(5)/CuO/Pt memristive devices with Ag point contacts at the interface exhibit forming-free and partial volatile analog resistive switching properties.Versatile synaptic functions,like the short-term plasticity,the long-term potentiation and the paired-pulse facilitation,are emulated with these devices.The Ag point contacts in the Ta_(2)O_(5)layer are verified through transmission electron microscope(TEM)and X-ray photoelectron spectroscope(XPS).The Ag point contacts at the interface endow the device the transition from the electrochemical metallization mode to the valence change mode,and the analog resistive switching behavior and neuromorphic functions.This interface engineering of introducing point contacts at the interface provides a way for the development of neuromorphic devices with low power consumption.
基金National Natural Science Foundation of China,Grant/Award Numbers:U22A20259,51732003,61974049,61874164,61841404National Key Research and Development Plan of MOST of China,Grant/Award Number:2019YFB2205100+3 种基金Interdisciplinary Research Program of Hust,Grant/Award Number:2023JCYJ043Hubei Key Laboratory for Advanced MemoriesHubei Engineering Research Center on MicroelectronicsChua Memristor Institute。
文摘Due to its non-invasive nature,ultrasound has been widely used for neuromodulation in biological systems,where its application influences the synaptic weights and the process of neurotransmitter delivery.However,such modulation has not been emulated in physical devices.Memristors are ideal electrical components for artificial synapses,but up till now they are hardly reported to respond to ultrasound signals.Here we design and fabricate a HfOx-based memristor on 64Y-X LiNbO_(3) single crystal substrate,and successfully realize artificial synapses modulation by shear-horizontal surface acoustic wave(SH-SAW).It is a prominent short-term resistance modulation,where ultrasound has been shown to cause resistance drop for various resistance states,which could fully recover after the ultrasound is shut off.The physical mechanism illustrates that ultrasound induced polarization potential in the HfOx dielectric layer acts on the Schottky barrier,leading to the resistance drop.The emulation of neuron firing frequency modulation through ultrasound signals is demonstrated.Moreover,the joint application of ultrasound and electric voltage yields fruitful functionalities,such as the enhancement of resistance window and synaptic plasticity through ultrasound application.All these promising results provide a new strategy for artificial synapses modulation,and also further advance neuromorphic devices toward system applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.51922023,61874011)the China Postdoctoral Science Foundation(Grant No.2021M703159)Fundamental Research Funds for the Central Universities(Grant No.E1EG6804).
文摘As key components of artificial afferent nervous systems,synaptic devices can mimic the physiological synaptic behaviors,which have attracted extensive attentions.Here,a flexible tribotronic artificial synapse(TAS)with bioinspired neurosensory behavior is developed.The triboelectric potential generated by the external contact electrification is used as the ion-gel-gate voltage of the organic thin film transistor,which can tune the carriers transport through the migration/accumulation of ions.The TAS successfully demonstrates a series of synaptic behaviors by external stimuli,such as excitatory postsynaptic current,paired-pulse facilitation,and the hierarchical memory process from sensory memory to short-term memory and long-term memory.Moreover,the synaptic behaviors remained stable under the strain condition with a bending radius of 20 mm,and the TAS still exhibits excellent durability after 1000 bending cycles.Finally,Pavlovian conditioning has been successfully mimicked by applying force and vibration as food and bell,respectively.This work demonstrates a bioinspired flexible artificial synapse that will help to facilitate the development of artificial afferent nervous systems,which is great significance to the practical application of artificial limbs,robotics,and bionics in future.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.12104462 and 62104134)support from the China Postdoctoral Science Foundation(Grant No.2021M700154)support from the Young Scholars Program of Shandong University。
文摘Memtransistor,a multi-terminal device that combines both the characteristics of a memristor and a transistor,has been intensively studied in two-dimensional layered materials(2 DLM),which show potential for applications in such as neuromorphic computation.However,while often based on the migration of ions or atomic defects in the conduction channels,performances of memtransistors suffer from the poor reliability and tunability.Furthermore,those known 2 DLM-based memtransistors are mostly constructed in a lateral manner,which hinders the further increasing of the transistor densities per area.Until now,fabricating non-atomic-diffusion based memtransistors with vertical structure remains challenging.Here,we demonstrate a vertically-integrated ferroelectric memristor by hetero-integrating the 2 D ferroelectric materials CuInP_(2)S_(6)(CIPS)into a graphite/CuInP_(2)S_(6)/MoS_(2)vertical heterostructure.Memristive behaviour and multi-level resistance states were realized.Essential synaptic behaviours including excitatory postsynaptic current,paired-pulse-facilitation,and spike-amplitude-dependent plasticity are successfully mimicked.Moreover,by applying a gate potential,the memristive behaviour and synaptic features can be effectively gate tuned.Our findings pave the way for the realization of novel gate-tunable ferroelectric synaptic devices with the capability to perform complex neural functions.
基金Project supported by the National Science and Technology Major Project of China(Grant No.2017ZX02301007-002)the National Key R&D Plan of China(Grant No.2017YFB0701701)the National Natural Science Foundation of China(Grant Nos.61774068 and 51772113).The authors acknowledge the support from Hubei Key Laboratory of Advanced Memories&Hubei Engineering Research Center on Microelectronics.
文摘Phase-change material(PCM)is generating widespread interest as a new candidate for artificial synapses in bioinspired computer systems.However,the amorphization process of PCM devices tends to be abrupt,unlike continuous synaptic depression.The relatively large power consumption and poor analog behavior of PCM devices greatly limit their applications.Here,we fabricate a GeTe/Sb2Te3 superlattice-like PCM device which allows a progressive RESET process.Our devices feature low-power consumption operation and potential high-density integration,which can effectively simulate biological synaptic characteristics.The programming energy can be further reduced by properly selecting the resistance range and operating method.The fabricated devices are implemented in both artificial neural networks(ANN)and convolutional neural network(CNN)simulations,demonstrating high accuracy in brain-like pattern recognition.
基金sponsored by the National Natural Science Foundation of China(Grant Nos 11574057,and 12172093)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515012607).
文摘Artificial synapse inspired by the biological brain has great potential in the field of neuromorphic computing and artificial intelligence.The memristor is an ideal artificial synaptic device with fast operation and good tolerance.Here,we have prepared a memristor device with Au/CsPbBr_(3)/ITO structure.The memristor device exhibits resistance switching behavior,the high and low resistance states no obvious decline after 400 switching times.The memristor device is stimulated by voltage pulses to simulate biological synaptic plasticity,such as long-term potentiation,long-term depression,pair-pulse facilitation,short-term depression,and short-term potentiation.The transformation from short-term memory to long-term memory is achieved by changing the stimulation frequency.In addition,a convolutional neural network was constructed to train/recognize MNIST handwritten data sets;a distinguished recognition accuracy of~96.7%on the digital image was obtained in 100 epochs,which is more accurate than other memristor-based neural networks.These results show that the memristor device based on CsPbBr3 has immense potential in the neuromorphic computing system.
基金supported by the National Key R&D Program of China(Nos.2022YFE0198200,2022YFA1200044)the National Science Fund for Distinguished Young Scholars of China(No.T2125005)+1 种基金the Tianjin Science Foundation for Distinguished Young Scholars(No.19JCJQJC61000)the Shenzhen Science and Technology Project(No.JCYj20210324121002008).
文摘A flexible organic artificial synapse(OAS)for tunable time-frequency signal processing was fabricated using a tri-blend film that had been fabricated using a one-step solution method.When combined with a chitosan film,this OAS can achieve an ultrashort-term retention time of only 49 ms for instant electricalcomputing applications;this is the shortest retention time yet achieved by a two-terminal artificial synapse.An array of these flexible OASs can withstand a high bending strain of 5%for 10^(4) cycles;this deformation endurance is a new record.The OAS was also sensitive to the number and frequency of electrical inputs;a tunable cut-off frequency enables dynamic filtering for use in image detail enhancement.This work provides a new resource for development of future neuromorphic computing devices。
基金the National Natural Science Foundation of China(Grant Nos.61703246 and 61703247)the Qingdao Science and Technology Plan Project(Grant No.19-6-2-2-cg)the Elite Project of Shandong University of Science and Technology。
文摘The synapse of human brain neurons is not only the transmission channel of information,but also the basic unit of human brain learning and information storing.The artificial synapse is constructed based on the Sr_(0.97)Ba_(0.03)TiO_(3-x)(SBT)memristor,which realizes the short-term and long-term plasticity of the synapse.The experiential learning and non-associative learning behavior in accordance with human cognitive rules are realized by using the SBT-memristor-based synapse.The process of synaptic habituation and sensitization is analyzed.This study provides insightful guidance for realization of artificial synapse and the development of artificial neural network.
