End Side Research Articles

A convection-enhanced flow field with height-changing ribs for redox flow batteries

Serpentine flow fields with flat ribs can effectively improve the performance of redox flow batteries. However, the marginal pressure difference between adjacent channels near the end side of ribs in conventional designs leads to weak convection in the regions, increasing the local concentration overpotential. This problem will be exacerbated in scaled-up redox flow battery stacks due to enlarged under-rib regions near the end side of ribs. In this work, two modified serpentine flow fields with height-changing ribs are proposed to adjust the electrode compression ratio at the under-rib region, thereby enhancing the convection in the electrode near the end side of ribs. Therefore, the active species are distributed more uniformly, resulting in an improved battery performance. Specifically, the uniformity of V2+, the energy efficiency and the system efficiency of the vanadium redox flow batteries with the ramp ribs are improved by 21 %, 2.7 %, and 2.7 % respectively compared with that of the conventional flat ribs, at the current density of 200 mA cm−2, the flow rate of 3.4 mL min−1 cm−2, and the active area of 117 cm2.

Optimum anastomosis angle of end-to-side microsurgical anastomosis for preventing future shear-related risk of thrombosis by computationalmodeling

End-to-side (ETS) microsurgical anastomosis is a powerful technique in microsurgery. It can overcome vessel’s diameter discrepancy and preserve the distal blood flow. Optimal angle of the ETS anastomosis has been debated and studied, and is currently limited to animal models. Computational model using Finite Element Analysis (FEA) was used to simulate the models with 45 (model45), 90 (model90), and 135 (model135) ETS anastomosis angles. Flow dynamics including flow velocity and wall shear rate were studied and compared. Maximum flow velocity ranged from the highest to the lowest in model135, model90, and model45, respectively. The velocity in model135 showed fluctuation flow. The maximum wall shear rate and distribution were highest in model45 and lowest in model90. ETS anastomosis angle of 90 degrees provided the most favourable flow dynamics to prevent shear related thrombosis in comparison to ETS anastomosis at 45 and 135 degrees.

Flexural behavior and numerical simulation of reinforced concrete beams with a UHPC stay-in-place formwork

To overcome the shortcomings of traditional concrete structures such as long construction cycle, high construction cost and poor durability, seven composite beams with a UHPC stay-in-place formwork (UCB) and one reinforced concrete (RC) beam were designed. An experimental study was conducted to investigate the flexural behavior of composite beams under the static load. The research parameters include formwork thickness, reinforcement rate, and formwork surface treatment. The results revealed that roughening the surface of UHPC formwork has a positive impact on enhancing the integrity of composite beams. The utilization of UHPC stay-in-place formwork can effectively improve the stiffness, cracking load, and peak load of members. Compared with that of the RC beam, the cracking load and peak load of composite beams increased by 63% ~ 103% and 6% ~ 15%, respectively, and the yielding stiffness increased by 23% ~ 41%. Different from the RC beam, new cracks occurred on one side of the initial crack's end and continued to extend upwards rather than along the original crack. The existence of a significant quantity of tiny cracks in composite beams effectively slowed down the increase in the width of pre-existing cracks in the early stage of loading. Due to the multi-crack pattern exhibited by the UHPC formwork, the strain concentration of the steel bars was effectively mitigated. When subjected to the same load level, the strain of the longitudinal steel bars in composite beams was smaller than that of the RC beam. The formula for calculating the flexural bearing capacity of composite beams is established through theoretical analysis. In addition, the numerical model of the composite beam is established by the finite element method (FEM). The influence of the contact method of the UHPC-NC interface on the flexural performance of the composite beam is explored. The supplementary analysis of the parametric study of the reinforcement rate and the UHPC formwork thickness is carried out. When using ABAQUS for the numerical analysis of the composite beam, it is appropriate to adopt the cohesion model or the Tie model for the UHPC-NC interface, and it is not appropriate to use the Coulomb friction model.

Instability monitoring of molten pool in pure copper laser welding based on a multi-scale cascade model and spatial optical signals

During laser welding of pure copper, instabilities such as violent molten pool oscillation, large spatters, and melt ejection severely damage weld quality, which are caused by copper’s high reflectivity on commonly used infrared laser. The seriously unstable molten pool and keyhole and complicated laser-material interactions result in complex process signal emission waveforms, adding to the difficulties in process stability monitoring tasks. In this work, to break down different contents in the complex signals and deeply analyzing signal-process relation, combinative spatial optical sensor system was designed, and time-frequency signal analysis in multi-scale windows was performed. It was found that the infrared radiation at the front and end side of molten pool indicates the oscillation behavior of liquid metal surface, and the signal fluctuation patterns of visible radiation from different height of metal vapor varied when meeting severe instability like melt ejections. Signal features were extracted based on the understanding of process mechanism and signal behaviors. A cascade model combining Artificial Neural Network (ANN) and Support Vector Machine (SVM) was introduced to predict weld seam quality, where the ANN model focused on short-time stability status perception and the SVM model was used to decide macroscopic seam formation defects based on combining outputs of the ANN model in a long-term sampling window. Application results showed that the recognition accuracy of pit was 100 % and the accuracy of uneven toe reached 86.3 %. The multi-source signals of unstable molten pool recognized by the cascade model were summarized. The evolution process of copper molten pool ejection was revealed.

Deciphering the actin structure-dependent preferential cooperative binding of cofilin.

The mechanism underlying the preferential and cooperative binding of cofilin and the expansion of clusters toward the pointed-end side of actin filaments remains poorly understood. To address this, we conducted a principal component analysis based on available filamentous actin (F-actin) and C-actin (cofilins were excluded from cofilactin) structures and compared to monomeric G-actin. The results strongly suggest that C-actin, rather than F-ADP-actin, represented the favourable structure for binding preference of cofilin. High-speed atomic force microscopy explored that the shortened bare half helix adjacent to the cofilin clusters on the pointed end side included fewer actin protomers than normal helices. The mean axial distance (MAD) between two adjacent actin protomers along the same long-pitch strand within shortened bare half helices was longer (5.0-6.3 nm) than the MAD within typical helices (4.3-5.6 nm). The inhibition of torsional motion during helical twisting, achieved through stronger attachment to the lipid membrane, led to more pronounced inhibition of cofilin binding and cluster formation than the presence of inorganic phosphate (Pi) in solution. F-ADP-actin exhibited more naturally supertwisted half helices than F-ADP.Pi-actin, explaining how Pi inhibits cofilin binding to F-actin with variable helical twists. We propose that protomers within the shorter bare helical twists, either influenced by thermal fluctuation or induced allosterically by cofilin clusters, exhibit characteristics of C-actin-like structures with an elongated MAD, leading to preferential and cooperative binding of cofilin.

Improving cyber-physical-power system stability through hardware-in-loop co-simulation platform for real-time cyber attack analysis

With advancements in communication systems and measurement technologies, smart grids have become more observable and controllable, evolving into cyber-physical-power systems (CPPS). The impact of network security and secondary equipment on power system stability has become more evident. To support the existing grid toward a smart grid scenario, smart metering plays a vital role at the customer end side. Cyber-Physical systems are vulnerable to cyber-attacks and various techniques have been evolved to detect a cyber attack in the smart grid. Weighted trust-based models are suggested as one of the most effective security mechanisms. A hardware-in-loop CPPS co-simulation platform is established to facilitate the theoretical study of CPPS and the formulation of grid operation strategies. This paper examines current co-simulation platform schemes and highlights the necessity for a real-time hard-ware-in-the-loop platform to accurately simulate cyber-attack processes. This consideration takes into account the fundamental differences in modeling between power and communication systems. The architecture of the co-simulation platform based on RT-LAB and OPNET is described, including detailed modeling of the power system, communication system, and security and stability control devices. Additionally, an analysis of the latency of the co-simulation is provided. The paper focuses on modeling and implementing methods for addressing DDOS attacks and man-in-the-middle at-tacks in the communication network. The results from simulating a 7-bus system show the effectiveness and rationality of the co-simulation platform that has been designed.

Evaluating the Direct CPT-Based Design Methods for Estimating the End Bearing and Side Resistance of Instrumented Test Piles

Evaluating the Direct CPT-Based Design Methods for Estimating the End Bearing and Side Resistance of Instrumented Test Piles

A theoretical model and verification of soil column deformation under impact load based on the Duncan-Chang model

The dynamic compaction method has been widely adopted in foundation treatment to densify the soil fillers. However, for the complexity of the impact behavior and soil mechanical properties, the theoretical research of dynamic compaction lags behind its practice for complex soil properties and stress paths. This paper presents a theoretical model applied to describe soil column plastic deformation under impact load. The relationship among stress increment, strain increment, and plastic wave velocity was derived from the aspect of propagation characteristics of stress waves in soil first. Combined with the Duncan-Chang Model, a one-dimensional theoretical model was established then. A numerical model was developed further to check the performance of the model. It showed that the deformation at the end of the soil column was mushroom-shaped. Both the axial and lateral deformation increased with the impact velocity. While some particles located at the side of the soil column end may splash under repeated impact. The theoretical deformations of the soil column were consistent with the experimental results both in the direction of axial and lateral.

End-to-Side Venous Anastomosis with IJV: Improving Outcomes of Microvascular Anastomosis in Head and Neck Reconstruction

Abstract Background End-to-side (ES) venous anastomosis is an established approach for head and neck reconstruction and has several benefits over conventional end-to-end (EE) anastomosis. However, this is not preferred by all, which may be due to technical preferences for an EE anastomosis by many surgeons. We present here our experience of routine ES venous anastomosis for head and neck reconstruction over the past 8 years. Materials and Methods All consecutive head and neck malignancy patients reconstructed with free flap and our routine ES internal jugular vein (IJV) anastomosis approach between 2015 and 2023 have been included in this study. Flap-related variables are reviewed retrospectively. Results Reconstruction was done with a total of 585 free flaps including 303 radial forearm flaps (RFFs), 143 osteocutaneous fibula flaps (OCFFs), and 139 anterolateral thigh (ALT) flaps. The flap survival rate was 573/585 (97.95%). Re-exploration and salvage rates were 45/585 (7.69%) and 38/45, respectively (84.44%). Conclusion Routine use of ES anastomosis simplifies microvascular anastomosis by avoiding efforts related to the selection of recipient vessels, providing a single large-caliber venous outlet, the favorable geometric orientation of the pedicle, and ease of re-exploration. The vascular anastomosis for RFF, ALT, and OCFF flap is feasible with 7–0 sutures and under 4.5X loupe magnification with this approach quite conveniently with similar outcomes to the reported flap survival rate in the contemporary practice.

Swash-Zone Formula Evaluation of Morphological Variation in Haeundae Beach, Korea

In this study, a swash-zone model, using Larson and Wamsley formula (LW07), was combined into the Telemac-2D model system to examine the performance of modeling swash-zone processes through comparisons with field observation data. The experimental site was the Haeundae Beach in South Korea where Typhoon Phanfone occurred in October 2014, and bathymetric surveys were performed before and after the typhoon. Hydrodynamic data were also measured to validate the modeled data. The performance of LW07 was tested by running the model in two modes, with and without LW07. First, the model was run to simulate the shoreline response to an imaginary coastal breakwater. The result showed a clear discrepancy between the two modes as the sediments were considerably cumulated behind the breakwater in the case with the swash-zone formula (LW07) in the wide range along the shoreline behind the breakwater, indicating that the sediments more actively and rapidly responded to the shadowing by the breakwater with LW07. The model was also run for a realistic case from August to October 2014, which included the typhoon’s period during 2–6 October. The results showed that the morphological changes at both ends of the beach in the swash zone were simulated with higher accuracy with LW07, supporting the effectiveness of LW07 in simulating the short-term morphological changes induced by the typhoon attack. In particular, the successful simulation of the sand accumulation at the end sides of the beach’s swash zone indicates that LW07 was effective in estimating not only the cross-shore transport but also longshore transport, which was likely due to the characteristics of LW07 that calculated sand transport in both directions. The enhanced modeling performance with LW07 was likely due to the adjustment of the sediment transport rate to the instantaneous changes in the local beach slope, which could successfully control the erosion/accretion process in the swash zone more realistically.

An end-cloud collaboration for state-of-charge estimation of lithium-ion batteries based on extended Kalman filter and convolutional neural network (CNN)—long short-term memory (LSTM)—attention mechanism (AM)

This paper introduces an innovative online state of charge (SOC) estimation method for lithium-ion batteries, designed to address the challenges of accurate and timely SOC estimation in electric vehicles under complex working conditions and computational limitations of on-board hardware. Central to this method is the concept of end-cloud collaboration, which harmonizes accuracy with real-time performance. The framework involves deploying a data-driven model on the cloud side for high-accuracy estimation, complemented by a fast model on the end side for real-time estimation. A crucial component of this system is the implementation of the extended Kalman filter on the end side, which fuses results from both ends to achieve high-accuracy and real-time online estimation. This method has been rigorously evaluated under various dynamic driving conditions and temperatures, demonstrating high accuracy, real-time performance, and robustness. The estimation results yield a root mean square error and mean absolute error of approximately 1.5% and 1%, respectively. Significantly, under the Cyber Hierarchy and Interactional Network framework, this method shows promising potential for extension to multi-state online cooperative estimation, opening avenues for advanced battery system management.

A Design Pattern of IAPVS Platform Based on Distributed Edge Computing

Abstract Traditional video surveillance is difficult to effectively cope with real-time interaction between end side devices of over ten thousand scale and data centers, and these devices are widely dispersed and deployed on a large scale. They cannot meet the needs of diverse scenarios monitoring and smart applications such as security, urban comprehensive management, ports, mines, water conservancy, power, industrial manufacturing and other fields. Based on the analysis of the problems in the popular intelligent video surveillance system, this paper proposes the design mode of an intelligent video surveillance intelligent analysis platform (IAPVS) based on distributed edge computing by improving the existing centralized video cloud computing architecture.This design pattern provides a new overall design solution for the development of platform of intelligent video analysis suitable for diverse scenarios and smart application fields.

Advancing glenohumeral dysplasia treatment in brachial plexus birth injury: the end-to-side spinal accessory to suprascapular nerve transfer technique

PurposeBrachial plexus birth injury (BPBI) is a common injury with the spectrum of disease prognosis ranging from spontaneous recovery to lifelong debilitating disability. A common sequela of BPBI is glenohumeral dysplasia (GHD) which, if not addressed early on, can lead to shoulder dysfunction as the child matures. However, there are no clear criteria for when to employ various surgical procedures for the correction of GHD.MethodsWe describe our approach to correcting GDH in infants with BPBIs using a reverse end-to-side (ETS) transfer from the spinal accessory to the suprascapular nerve. This technique is employed in infants that present with GHD with poor external rotation (ER) function who would not necessitate a complete end-to-end transfer and are still too young for a tendon transfer. In this study, we present our outcomes in seven patients.ResultsAt presentation, all patients had persistent weakness of the upper trunk and functional limitations of the shoulder. Point-of-care ultrasounds confirmed GHD in each case. Five patients were male, and two patients were female, with a mean age of 3.3 months age (4 days–7 months) at presentation. Surgery was performed on average at 5.8 months of age (3–8.6 months). All seven patients treated with a reverse ETS approach had full recovery of ER according to active movement scores at the latest follow-up. Additionally, ultrasounds at the latest follow-up showed a complete resolution of GHD.ConclusionIn infants with BPBI and evidence of GHD with poor ER, end-to-end nerve transfers, which initially downgrade function, or tendon transfers, that are not age-appropriate for the patient, are not recommended. Instead, we report seven successful cases of infants who underwent ETS spinal accessory to suprascapular nerve transfer for the treatment of GHD following BPBI.

The sucker-like end-to-side arterial anastomosis for free flap in extremities reconstruction: a retrospective study of 78 cases

BackgroundThe application of end-to-side (ETS) anastomosis for flap transfer poses challenges, particularly in cases of significant size discrepancy between the donor and flap arteries. Herein, a novel ETS anastomosis technique, termed “sucker-like ETS anastomosis”, is developed to mitigate and rectify such vessel discrepancies. This study aims to evaluate the efficacy of this technique in tissue defect reconstruction through free flap transfer.MethodsBetween September 2018 and March 2023, the medical records and follow-up data of 78 patients who underwent free flap transfer using sucker-like ETS anastomosis for significant artery size discrepancies were collected and retrospectively analyzed.ResultsAmong the 78 cases that received free flap transfer, the range of artery size discrepancy (flap artery vs donor artery) was 1:1.6–1:4 (mean: 1:2.5). Following anastomosis with the sucker-like ETS technique, 75 cases achieved flap survival without requiring additional surgical intervention, yielding a one-stage success rate of 96.2%. Three cases experienced post-operative venous crises, with two cases surviving after vein exploration and one case undergoing flap necrosis, necessitating a secondary skin graft. Seven cases faced delayed wound healing but eventually achieved complete healing following dressing changes. No arterial crisis was observed during hospitalization. With an average follow-up of 13 months, the surviving flaps exhibited excellent vitality without flap necrosis or pigment deposition. Overall, the application of sucker-like ETS arterial anastomosis for flap transfer resulted in a high overall surgical success rate of 98.7% (77/78).ConclusionThe application of sucker-like ETS anastomosis for free flap transfer is highly effective, particularly in cases with significant size discrepancy between the recipient and donor arteries.

Intraoperative evaluation of local cerebral hemodynamic change by laser speckle contrast imaging for predicting postoperative cerebral hyperperfusion during STA-MCA bypass in adult patients with moyamoya disease

Cerebral hyperperfusion (CHP) occurred frequently after direct superficial temporal artery–middle cerebral artery (STA-MCA) bypass surgery for moyamoya disease (MMD). We analyzed cortical microvascular density (CMD) and the change of cerebral blood flow (LΔCBF) using intraoperative laser speckle contrast imaging (LSCI) on 130 hemispheres of 95 consecutive adult patients with MMD. The demographic characteristics, cortical hemodynamic sources, bypass methods, intraoperative blood flow data, and relative CBF changes on single-photon emission computed tomography (SPECT) examination (SΔrCBF) were compared between the groups with and without CHP. The median values for CMD, LΔCBF, and SΔrCBF were significantly higher in the CHP group than in the non-CHP group (CMD 0.240 vs 0.206, P = 0.004; LΔCBF 2.285 vs 1.870, P < 0.001; SΔCBF 1.535 vs 1.260, P < 0.001). Multivariate analysis revealed that hemodynamic sources of recipient parasylvian cortical arteries from MCA (M-PSCAs), end-to-side (E-S) bypass method, CMD ≥ 0.217, and LΔCBF ≥ 1.985 were the risk factors for CHP. Intraoperative LSCI was useful for evaluating hemodynamics and predicting CHP in patients with MMD.

A–D–A'–D–A type nonfused ring electron acceptors for efficient organic solar cells via synergistic molecular packing and orientation control

AbstractNonfused ring electron acceptors (NFREAs) are promising candidates for future commercialization of organic solar cells (OSCs) due to their simple synthesis. Still, the power conversion efficiencies (PCEs) of NFREA‐based OSCs have large room for improvement. In this work, by merging end group halogenation and side chain engineering, we developed four A–D–A'–D–A type NFREAs, which we refer to as EH‐4F, C4‐4F, EH‐4Cl, and C4‐4Cl. Single crystal X‐ray diffraction revealed that multiple intermolecular S···F interactions between cyclopentadithiophene and 5,6‐difluoro‐3‐(dicyanomethylene)indanone could cause an unfavorable dimer formation, leading to ineffective π–π stackings in EH‐4F and C4‐4F, whereas no such dimer was found in EH‐4Cl and C4‐4Cl after replacing with 5,6‐dichloro‐3‐(dicyanomethylene)indanone. Moreover, although the shorter n‐butyl side chain resulted in a closer molecular packing in C4‐4Cl, EH‐4Cl (2‐ethylhexyl substitution) with proper crystallinity exhibited enhanced face‐on orientation in thin film, which is favorable for vertical charge transport and further reducing charge recombination. As a result, a PCE of 13.0% is obtained for EH‐4Cl‐based OSC with a fill factor of 0.70. This work highlights the importance of molecular packing and orientation control toward future high‐performance A–D–A'–D–A type NFREAs.

Smart Actuation for End-Edge Industrial Control Systems

Along with the fourth industrial revolution, industrial automation systems are evolving into a multi-tier end-edge computing architecture. Edge controllers, which are equipped with a larger computing capacity compared to local controllers, can communicate with local plants over mainstream wireless networks such as WirelessHART, Wi-Fi, and cellular networks. Well-known challenges induced by networks, such as uncertain time delays and packet drops, have been intensively investigated from various perspectives: control synthesis, network design, or control and network co-design. The status quo is that the industry remains hesitant to close the loop between the edge controller and the actuation side due to safety concerns. This work offers an alternative perspective to address the safety concern, by exploiting the design freedom of an end-edge computing architecture. Specifically, we present a smart actuation framework, which deploys (1) an edge controller, which communicates with physical plant via wireless network, accounting for optimality, adaptation, and constraints by conducting computationally expensive operations; (2) a smart actuator, which is co-located with the physical plant on the end tier and executes a local control policy, accounting for system safety in the view of network imperfections, (3) the end-edge control co-design strategies and cooperation logic for both performance and stability. For certain classes of plants, semi-globally asymptotic stability of the resulting end-edge control systems is established when the edge controller is the model predictive control (MPC), or policy iteration-based learning control. We also provide an adaptation strategy for the end-edge control systems facing model parameter mismatches when the edge controller employs reinforcement learning. Extensive simulations demonstrate the advantages of the proposed end-edge co-design and cooperation procedures. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —Edge computing is gaining momentum in areas that require low latency and high efficiency, i.e., mobile computing, video analytics, and autonomous driving. Industrial automation systems are also evolving into a multi-tier end-edge computing architecture. It pays obvious dividends to leverage the cooperation between end and edge, benefiting from fast and reliable communication on the end side, and powerful computation capacity on the edge side. The current end-edge cooperation focuses on how to partition tasks and offload computation resources in order to minimize delay and energy consumption, as well as how to balance the tradeoff between them. However, the impacts of end-edge cooperation on the safety, optimality, and cost of industrial automation have not been systematically studied. This paper aims to tailor end-edge cooperation in a smart actuation framework, for industrial automation to reconcile the above aspects by leveraging co-design of end and edge controllers and their switching logic. Extensive pure and semi-physical simulations demonstrate the advantages in performance and system stability of the proposed end-edge co-design and cooperation procedures.

Fungi Associated with Post-harvest Losses of Multani Mango

The Multani mango, renowned for its exceptional taste and aromatic profile, is a cultivar thriving in the fertile soils of Multan, Pakistan, representing a cherished tropical delicacy. Despite its esteemed status in the region's mango-producing legacy, a formidable challenge arises from its limited shelf life. Fungal pathogens associated with the mango curtail its shelf life and detrimentally impact fruit yield and quality. This study aimed to isolate and identify fungal pathogens linked to Mango anthracnose, stem end rot, side rot, and fruit fly attack symptoms. Ten mango fruits exhibiting symptoms were systematically sampled from three distinct markets in Multan, totalling 30 fruits for each disease symptom category. Isolation and identification outcomes revealed that in mangoes displaying anthracnose symptoms, Colletotrichum gloeosporoides was present in 100% of fruit samples, followed by Aspergillus fumigatus (72.72%). For mango fruits with stem end rot, Botryodiplodia theobromae was identified in 90.90% of samples, followed by Colletotrichum gloeosporoides (70%). Fruits exhibiting symptoms of fruit fly attack and side rot contained Aspergillus flavus in 99.90% and 88.81% of samples, respectively. These findings underscore the pivotal role of fungal pathogens in the Multani mango's shelf-life predicament, necessitating strategic interventions in cultivation and post-harvest handling. The identification of specific pathogens provides valuable insights for targeted management practices aimed at preserving the quality and extending the shelf life of this esteemed mango cultivar.

Versatile Neuromorphic Modulation and Biosensing based on N-type Small-molecule Organic Mixed Ionic-Electronic Conductors.

The ion/chemical-based modulation feature of organic mixed ionic-electronic conductors (OMIECs) are critical to advancing next generation bio-integrated neuromorphic hardware. Despite achievements with polymeric OMIECs in organic electrochemical neuronal synapse (OENS). However, small molecule OMIECs based OENS has not yet been realized. Here, for the first time, we demonstrate an effective materials design concept of combining n-type fused all-acceptor small molecule OMIECs with subtle side chain optimization that enables robustly and flexibly modulating versatile synaptic behavior and sensing neurotransmitter in solid or aqueous electrolyte, operating in accumulation modes. By judicious tuning the ending side chains, the linear oligoether and butyl chain derivative gNR-Bu exhibits higher recognition accuracy for a model artificial neural network (ANN) simulation, higher steady conductance states and more outstanding ambient stability, which is superior to the state-of-art n-type OMIECs based OENS. These superior artificial synapse characteristics of gNR-Bu can be attributed to its higher crystallinity with stronger ion bonding capacities. More impressively, we unprecedentedly realized n-type small-molecule OMIECs based OENS as a neuromorphic biosensor enabling to respond synaptic communication signals of dopamine even at sub-μM level in aqueous electrolyte. This work may open a new path of small-molecule ion-electron conductors for next-generation ANN and bioelectronics.

Versatile Neuromorphic Modulation and Biosensing based on N‐type Small‐molecule Organic Mixed Ionic‐Electronic Conductors

AbstractThe ion/chemical‐based modulation feature of organic mixed ionic‐electronic conductors (OMIECs) are critical to advancing next generation bio‐integrated neuromorphic hardware. Despite achievements with polymeric OMIECs in organic electrochemical neuronal synapse (OENS). However, small molecule OMIECs based OENS has not yet been realized. Here, for the first time, we demonstrate an effective materials design concept of combining n‐type fused all‐acceptor small molecule OMIECs with subtle side chain optimization that enables robustly and flexibly modulating versatile synaptic behavior and sensing neurotransmitter in solid or aqueous electrolyte, operating in accumulation modes. By judicious tuning the ending side chains, the linear oligoether and butyl chain derivative gNR‐Bu exhibits higher recognition accuracy for a model artificial neural network (ANN) simulation, higher steady conductance states and more outstanding ambient stability, which is superior to the state‐of‐art n‐type OMIECs based OENS. These superior artificial synapse characteristics of gNR‐Bu can be attributed to its higher crystallinity with stronger ion bonding capacities. More impressively, we unprecedentedly realized n‐type small‐molecule OMIECs based OENS as a neuromorphic biosensor enabling to respond synaptic communication signals of dopamine even at sub‐μM level in aqueous electrolyte. This work may open a new path of small‐molecule ion‐electron conductors for next‐generation ANN and bioelectronics.