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Stretchable conducting polymer PEDOT:PSS treated with hard-cation-soft-anion ionic liquid designed from molecular modeling
Get PDFPEDOT:PSS, an ionic polymer mixture of positively-charged poly-3,4-ethylenedioxythiophene (PEDOT+) and negatively-charged poly-styrenesulfonate (PSS−), is a water-processable and environmentally-benign organic semiconductor and electrochemical transistor, which plays a key role in organic (bio)electronic devices. However, pristine PEDOT:PSS films form 10-to-30-nm granular domains, where conducting-but-hydrophobic PEDOT-rich cores are surrounded by hydrophilic-but-insulating PSS-rich shells. Such morphology makes PEDOT:PSS water-soluble and thermally stable but very poor in conductivity. A tremendous amount of effort has been made to enhance the conductivity of PEDOT:PSS by restoring the extended conduction network of PEDOT. Recently, remarkable ~5000-fold improvements of conductivity have been achieved by mixing PEDOT:PSS with proper ionic liquids (ILs). In a series of free energy estimations using density functional theory calculation and molecular dynamics simulation, we have demonstrated that the classic hard-soft acid–base (or cation-anion) principle of chemistry plays an important role in such improvements. Ion exchange between PEDOT+:PSS− and A+:X− ILs helps PEDOT+ to decouple from PSS− and to grow into large-scale conducting domains of π-stacked PEDOT+ decorated by IL anions X−. Thus, the most spontaneous decoupling between soft (hydrophobic) PEDOT+ and hard (hydrophilic) PSS− would be induced by strong interaction with soft anions X− and hard cations A+, respectively. Such hard-cation-soft-anion principles have led us to design ILs containing extremely hydrophilic (i.e., protic) cations and hydrophobic anions. Not only they indeed improve the conductivity of PEDOT:PSS but also enhance its stretchability as well. In summary, our modeling offered molecular-level insights on the morphological, electrical, and mechanical properties of PEDOT:PSS and a molecular-interaction-based enhancement strategy for intrinsically stretchable conductive polymers. © 2024 The Author(s). Bulletin of the Korean Chemical Society published by Korean Chemical Society and Wiley-VCH GmbH.TRUEsciescopuskc
Dipeptidyl peptidase 4 as an injury-responsive protein in the mouse sciatic nerve
Get PDFDipeptidyl peptidase 4 (DPP4) is a membrane-bound protease known for its roles in immunity and metabolism; however, its function in the nervous system remains largely unexplored. We found that DPP4 is predominantly expressed in the Schwann cells of the sciatic nerve, and its systemic depletion in postnatal mice resulted in a decline in motor function. Importantly, the inhibition of its proteolytic activity did not affect axon regeneration, indicating that DPP4′s protease activity may not be directly involved in axon regeneration. Instead, we observed a reduction in DPP4 protein levels in the sciatic nerve after injury and increased in serum postinjury, suggesting that DPP4 may be shed into circulation, potentially mediating systemic responses following injury. These findings highlight DPP4′s importance in sensory function and its potential role in systemic responses after peripheral nerve injury. © 2024 The Author(s)TRUEsciescopuskc
Flex-to-Stretch Hybrid Electronics–Bonding-Free Robust Interface for Wearable Wireless Physiological Monitoring
No full textHybrid electronics require a robust mechanical interface between externally fabricated stretchable sensors and flexible printed circuit boards (FPCBs) to obtain stable electrophysiological information. The most advanced technique for the integration of FPCBs with stretchable sensors is anisotropic conductive film bonding. Fabricating high-performance sensors requires microfabrication techniques, such as photolithography and etching, which are cumbersome and expensive. Therefore, a sensor fabrication process that supports FPCB manufacturing with lower complexity and cost is required. Herein, we propose a bonding-free approach for fabricating FPCBs and stretchable sensors on a single substrate. This approach utilizes in-and out-of-plane mechanical gradients to obtain a robust and durable mechanical interface for a smooth transition of the internal mechanical stress compliance, as confirmed by experiments and simulations. The gradient mesh patterns, without ACF bonding, can withstand tensile strains of over 30% before experiencing electrical breakdown. Additionally, Kirigami-inspired mesh patterns can extend stretchability by over 100%. The electrical performance of temperature sensors (linear response to temperature changes) and ECG sensors (clear visibility of PQRST peaks) remains stable under various physical activities. User-accessible, facile laser ablation and cutting techniques compatible with the FPCB manufacturing process were employed to fabricate stretchable sensors. This approach enables the development of FPCB-compatible on-skin stretchable sensors with robust mechanical properties. AuthorsTRUEsciescopu
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No full textHigh-detectivity silver telluride nanoparticle-based near-infrared photodetectors functionalized with surface-plasmonic gold nanoparticles
No full textHerein, the performance of near-infrared (NIR) photodetectors fabricated through a combination of AgxTe films comprising colloidal AgxTe nanoparticles (NPs) with plasmonic Au NPs was investigated. The surface-plasmonic Au NPs on low-bandgap AgxTe considerably enhanced the detectivity of NIR photodetectors. The Au NPs formed on the AgxTe surface triggered localized surface-plasmon resonance and increased light absorption, hot-carrier injection, and silver telluride crystallinity during an additional annealing process, which was required to form Au NPs from thermally deposited thin Au layers. Under illumination using an 808-nm laser, the detectivity of the as-fabricated Au NP–decorated AgxTe photodetectors was 7.17 × 1011 cmHz1/2 W−1. Compared with that of pristine AgxTe photodetectors, the detectivity of the prepared photodetectors was seven-fold higher; this detectivity was superior to those of devices based on MoS2, arsenic phosphorus, and SnTe nanoplates and commercial photosensors at room temperature. Thus, the proposed strategy of combining AgxTe films with surface-plasmonic Au NPs for enhanced performance of NIR photodetectors provides a new approach for realizing next-generation optoelectronic devices for detection in the NIR region. © 2024 Elsevier B.V. All rights reserved.FALSEsciescopu
Electric stent with Self-generation function
No full text본 발명은 스텐트가 발전 기능을 구비하여 자체에 장착된 전자소자 또는 다른 장치에 장착되어 인체에 삽입된 전자 소자로 구동 전원을 공급할 수 있도록, 스텐트; 및 상기 스텐트에 장착되어 상기 스텐트의 압력 변화 또는 상기 스텐트 내부의 유체 흐름에 의해 발전을 수행하는 발전소자에 의해 생산된 전력을 내부 전자소자 또는 외부 전자 소자로 출력하는 발전모듈;을 포함하여 구성되는 것을 특징으로 하는 발전 기능을 가지는 전자스텐트를 제공한다
Investigation of calsyntenin-3 functions as a novel group I metabotropic glutamate receptor- binding protein.
No full textMetabotropic glutamate receptor group 1의 새로운 결합 단백질인 Calsyntenin-3의 기능에 대한 연구I. Introduction
1.1 Synapses play a role in information processing and transmission 1
1.2 Synaptic adhesion molecules (SAMs) orchestrate synapse development and function 3
1.3 Heterogeneous functions of Clstn protein family 4
1.3.1 Clstn1 is involved in excitatory synapses 5
1.3.2 Clstn2 knockout leads to reduced inhibitory synapses 6
1.3.3 Clstn3 regulates excitatory synaptic innervation 6
1.4 Glutamate receptors come in two main types: ionotropic (iGluR) and metabotropic (mGluR) 9
1.4.1 Molecular structure and functions of mGluRs 10
1.4.2 mGluR5 is related to LTP and LTD 12
1.4.3 mGluR5 is activated through dimerization 14
1.4.4 mGluR5 signaling pathway is involved in synaptic plasticity, memory, and cognition 14
II. Material and Methods
2.1 Animal 17
2.2 Cell-surface binding assays 18
2.3 Preparation of Adeno-Associated Viruses and Titration 18
2.4 Electrophysiology 19
2.5 Behavior test 23
2.6 Pharmacological rescue 24
2.7 Statistical analysis 24
III. Results
3.1 Deficiency of Clstn3 affects synaptic function in CaMKIIα-Clstn3 mice 26
3.1.1 Excitatory synaptic transmission is reduced in CA1 pyramidal neurons of CaMKIIα-Clstn3 mice 26
3.1.2 Evoked synaptic responses are reduced in CA1 pyramidal neurons of CaMKIIα-Clstn3 mice 28
3.1.3 Synaptic transmission of mPFC pyramidal neurons is not affected in CaMKIIα-Clstn3 mice 30
3.1.4 Both AMPAR and NMDAR-dependent EPSCs are not altered in mPFC of CamKIIα-Clstn3 mice 31
3.2 Clstn3 deficient affects synaptic function in CA1-specific Clstn3-cKO mice 32
3.2.1 Basal synaptic transmission is not affected CA1-specific Clstn3-cKO mice 32
3.2.2 AMPAR-mediated synaptic responses are enhanced in Clstn3-deleted CA1 pyramidal neurons 33
3.3 Social hierarchy is not altered in CA1-specific Clstn3-cKO mice 34
3.4 Clstn3 deficient affects synaptic function in mPFC-specific Clstn3-cKO mice 34
3.4.1 Excitatory synaptic transmission is increased in Clstn3-deleted mPFC pyramidal neurons 34
3.4.2 NMDAR-mediated synaptic responses are enhanced in Clstn3-deleted mPFC pyramidal neurons 36
3.5 Social hierarchy is reduced in mPFC-specific Clstn3-cKO mice 37
3.6 MTEP treatment reverses social hierarchy in mPFC-specific Clstn3-cKO mice 38
IV. Figure 40
V. Discussion 66
VI. Reference 72
VII. 요약문 80MasterdCollectio
Data-driven Motion Control Framework of Model-based Approach for Multi-axis Flexible System
No full textData-driven optimization;Model-based control;System identification;Order selection;Disturbance observer;Convex optimization;MIMO flexible systemsThis thesis introduces a novel data-driven motion control framework that synergistically integrates with a model-based approach, specifically tailored for the control of multi-axis flex- ible systems. Traditional model-based control strategies, while robust, often require precise mathematical models that can be computationally intensive and difficult to obtain for complex systems. Conversely, purely data-driven methods, though adaptive and less reliant on model accuracy, can lack the theoretical robustness of model-based approaches. This work bridges this gap by developing an innovative algorithm that leverages the strengths of both paradigms. This means leveraging measured data to improve and optimize model-based controllers. The proposed framework rests on an iterative algorithm that uses measured data to converge on optimal control parameters, minimizing reliance on a priori system models and accommodating system non-linearities and uncertainties. This methodology is based on a rigorous theoretical foundation encompassing system identification techniques, optimization algorithms, and stability analysis to ensure that the con- trol framework not only adapts to the inherent flexibility and dynamics of the system, but also complies with performance criteria. Extensive simulation and experimental studies are presented that demonstrate the effec- tiveness of the data-driven control framework in managing the complexity of multi-axis flexible systems. Results indicate significant improvements in system performance through improved robustness to model inconsistencies, improved suppression of unmodeled dynamics and exter- nal disturbances. In summary, this paper contributes to the control engineering domain by presenting a con- trol framework that optimizes model-based control strategies through data-driven methods. The implications of this study are far-reaching and provide a versatile control architecture that can be extended to a variety of multi-axis flexible systems within a variety of industrial applications. Keywords: Data-driven optimization, Model-based control, System identification, Order se- lection, Disturbance observer, Convex optimization, MIMO flexible systems|이 논문은 특히 다축 유연한 시스템의 제어를 위해 맞춤화된 모델 기반 접근 방식과 시너지 효과적으로 통합되는 새로운 데이터 기반 모션 제어 프레임워크를 소개합니다. 전통적인 모델 기반 제어 전략은 강력하기는 하지만 계산 집약적이고 복잡한 시스템에서는 얻기 어려운 정밀한 수학적 모델이 필요한 경우가 많습니다. 반대로, 순전히 데이터 기반 방법은 적응성이 뛰어나고 모델 정확도에 덜 의존하지만 모델 기반 접근 방식의 이론적 견고성이 부족할 수 있습니다.
이 작업은 두 패러다임의 장점을 활용하는 혁신적인 알고리즘을 개발하여 이러한 격차를 해소합니다. 이는 측정된 데이터를 활용하여 모델 기반 컨트롤러를 개선하고 최적화하는 것을 의미합니다. 제안된 프레임워크는 측정된 데이터를 사용하여 최적의 제어 매개변수에 수렴하고 선험적 시스템 모델에 대한 의존도를 최소화하며 시스템 비선형성 및 불확실성을 수용하는 반복 알고리즘을 기반으로 합니다.
이 방법론은 제어 프레임워크가 시스템의 고유한 유연성과 역동성에 적응할 뿐만 아니라 성능 기준도 준수하도록 보장하기 위해 시스템 식별 기술, 최적화 알고리즘 및 안정성 분석을 포괄하는 엄격한 이론적 기반을 기반으로 합니다.
다축 유연한 시스템의 복잡성을 관리하는 데 있어 데이터 기반 제어 프레임워크의 효율성을 입증하는 광범위한 시뮬레이션 및 실험 연구가 제시됩니다. 결과는 모델 불일치에 대한 견고성 향상, 모델링되지 않은 역학 및 외부 방해에 대한 억제 향상을 통해 시스템 성능이 크게 향상되었음을 나타냅니다.
요약하면, 본 논문은 데이터 기반 방법을 통해 모델 기반 제어 전략을 최적화하는 제어 프레임워크를 제시함으로써 제어 엔지니어링 영역에 기여합니다. 이 연구의 의미는 광범위하며 다양한 산업 응용 분야 내에서 다양한 다축 유연한 시스템으로 확장할 수 있는 다목적 제어 아키텍처를 제공합니다.List of Contents
Abstract i
List of Contents . ii
List of Tables vii
List of Figures viii
I.INTRODUCTION . 1
1.1 RESEARCH BACKGROUND 1
1.2 LITERATURE REVIEW AND PROBLEM STATEMENTS . 2
1.2.1 Decoupling Control for Dual-Drive Gantry Stage 2
1.2.2 Parametric System Identification Using Frequency Response Function . 4
1.2.3 Data-Driven Optimization for Model-based Controller 7
1.3 CONTRIBUTION POINTS OF THESIS 9
1.4 OUTLINE OF THESIS 12
II.MULTI-INPUT-MULTI-OUTPUT SYSTEM DECOMPOSITION
FROM FREQUENCY RESPONSE PERSPECTIVE . 14
2.1 INTRODUCTION 14
2.2 PROBLEM FORMULATION: ANALYSIS OF COUPLING DYNAMICS 16
2.2.1 Dynamics Analysis of the Dual-drive Gantry Stage 16
2.2.2 Mechanical Coupling in Conventional Actuator-based Dynamics . 18
2.2.3 Effect of Coupling in Actuator-based Dynamics . 20
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2.3 DATA-DRIVEN MODE DECOMPOSITION AND RECONFIGURED DY-
NAMICS FROM PERSPECTIVE OF TASK-BASED MOTIONS . 23
2.3.1 Canonical Polyadic Decomposition-based Dynamics Analysis 24
2.3.2 Reconfiguration of Dual-drive Gantry System Dynamics based on CPD
and Task Motion 27
2.4 DESIGN AND ANALYSIS OF TWO-DEGREE-OF-FREEDOM CASCADE
CONTROL BASED ON TASK-BASED DYNAMICS . 31
2.4.1 Application of Task-based Dynamics for Model-based Cascade Control 32
2.4.2 Improvement of Robust Stability of the Model-based Control using
Task-based Dynamics 35
2.5 EXPERIMENTAL RESULTS 37
2.5.1 Experimental Set-up 37
2.5.2 Improvement of Bandwidth by the Proposed Controller 37
2.5.3 Robust Performance Improvement of Task-based Disturbance Observer
against Additional Mass . 40
2.5.4 Decoupling Effect by the Proposed Mode Decomposition and Control . 42
2.6 CONCLUSION . 44
III.SYSTEM PARAMETRIC IDENTIFICATION BASED ON RO-
BUST STABILITY CRITERION 45
3.1 INTRODUCTION 45
3.2 ANALYSIS OF DISTURBANCE OBSERVER AND OPTIMIZATION CHAR-
ACTERISTICS . 47
3.2.1 Design of Disturbance Observer 48
– iii –
3.2.2 Robust Stability Margin Analysis of Disturbance Observer . 50
3.2.3 Cost Function Design and Its Convexity 51
3.3 DISTURBANCE OBSERVER RELEVANT PARAMETRIC SYSTEM IDEN-
TIFICATION 53
3.3.1 Brief of Weighted Iterative Least Square Algorithm using Modeling Error 53
3.3.2 DOB-Relevant System Identification . 55
3.3.3 ℓ2-norm approximation for ℓ∞-norm?? 57
3.3.4 Procedure of the DOB-relevant system identification algorithm 58
3.4 EXPERIMENTAL VERIFICATION 60
3.4.1 Condition and Setting 60
3.4.2 Performance Validation Compared to the Conventional Method . 61
3.4.3 Characteristics of DOB-relevant Identification According to Desired
Bandwidth 66
3.5 CONCLUSION AND FUTURE WORKS 70
IV.MODEL ORDER SELECTION RELATED TO ROBUST STABIL-
ITY CRITERION . 71
4.1 INTRODUCTION 72
4.2 PROBLEM FORMULATION 73
4.2.1 Disturbance Observer based on Nominal Model . 73
4.2.2 Parametric Identification with Noisy & Discrete Data and Model Order
Selection 74
4.3 PARAMETRIC IDENTIFICATION BASED ON FREQUENCY RESPONSE
FUNCTION 76
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4.3.1 System Description based on Frequency Response Model . 76
4.3.2 Parametric Identification using Frequency Response Model . 77
4.4 MODEL ORDER SELECTION BASED ON ROBUST STABILITY 79
4.5 NUMERICAL SIMULATION OF PROPOSED METHOD 81
4.5.1 Simulation Condition and Setting 81
4.5.2 Model order selection based on robust stability criterion 83
4.6 CONCLUSION AND FUTURE WORKS 85
V.DATA-DRIVEN CONTROL OPTIMIZATION FRAMEWORKS FOR
MODEL-BASED CONTROLLER . 86
5.1 INTRODUCTION 86
5.1.1 Backgrounds . 86
5.1.2 Studies on Data-driven Controller Tuning . 88
5.1.3 Novel Data-driven Optimization Algorithm 89
5.2 ANALYSIS OF INTEGRATED CONTROL AND OPTIMIZATION CHAR-
ACTERISTICS . 91
5.2.1 Design of Integrated Control 91
5.2.2 Cost Function Design for Optimization and Its Convexity 93
5.2.3 Robust Stability Analysis for Integrated Control . 95
5.3 PROPOSED DATA-DRIVEN INTEGRATED CONTROLLER OPTIMIZATION100
5.3.1 Iterative Feedback Tuning 99
5.3.2 Gradient Calculation for Integrated Control 101
5.3.3 Unbiased Estimation of Cost Function Gradient . 104
5.3.4 Convergence Analysis 106
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5.4 EXPERIMENTAL VERIFICATION 107
5.4.1 Experimental Set-up 108
5.4.2 Optimization Performance with Different Initial Control Parameters 109
5.4.3 Optimization Performance With Various Plant Conditions . 112
5.5 CONCLUSION . 116
VI.INTEGRATED PROCEDURE OF THESIS RESEARCH 117
6.1 BRIEF OF INTEGRATED PROCEDURE 117
6.2 ENTIRE PROCEDURE OF 118
6.2.1 Frequency response & initial setting . 118
6.2.2 Data-based system decoupling . 120
6.2.3 DOB-relevant system identification with order selection algorithm 122
6.2.4 Data-driven control parameter optimization 124
6.3 CONCLUSION . 126
VII.CONCLUSION AND RECOMMANDATION 127
7.1 CONCLUSIONS 127
VIII.ACHIEVEMENTS 128
8.1 Journal Papers 128
8.2 International Conference Papers . 128
8.3 Domestic Conference Papers 130
8.4 Awards 130
References . 131
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Sequential Effect of Dual-Layered Hybrid Graphite Anodes on Electrode Utilization During Fast-Charging Li-Ion Batteries
Get PDFTo recharge lithium-ion batteries quickly and safely while avoiding capacity loss and safety risks, a novel electrode design that minimizes cell polarization at a higher current is highly desired. This work presents a dual-layer electrode (DLE) technology via sequential coating of two different anode materials to minimize the overall electrode resistance upon fast charging. Electrochemical impedance spectroscopy and distribution of relaxation timesanalysis revealed the dynamic evolution of electrode impedances in synthetic graphite (SG) upon a change in the state of charge (SOC), whereas the natural graphite (NG) maintains its original impedance regardless of SOC variation. This disparity dictates the sequence of the NG and SG coating layers within the DLE, considering the temporal SOC gradient developed upon fast charging. Simulation and experimental results suggest that DLE positioning NG and SG on the top (second-layer) and bottom (first-layer), respectively, can effectively reduce the overall resistance at a 4C-rate (15-min charging), demonstrating two times higher capacity retention (61.0%) over 200 cycles than its counterpart with reversal sequential coating, and is higher than single-layer electrodes using NG or NG/SG binary mixtures. Hence, this study can guide the combinatorial sequence for multi-layer coating of various active materials for a lower-resistivity, thick-electrode design. © 2024 The Authors. Advanced Science published by Wiley-VCH GmbH.TRUEsciescopu
Simulated augmented reality-based calibration of optical see-through head mound display for surgical navigation
No full textPurposeCalibration of an optical see-through head-mounted display is critical for augmented reality-based surgical navigation. While conventional methods have advanced, calibration errors remain significant. Moreover, prior research has focused primarily on calibration accuracy and procedure, neglecting the impact on the overall surgical navigation system. Consequently, these enhancements do not necessarily translate to accurate augmented reality in the optical see-through head mount due to systemic errors, including those in calibration.MethodThis study introduces a simulated augmented reality-based calibration to address these issues. By replicating the augmented reality that appeared in the optical see-through head mount, the method achieves calibration that compensates for augmented reality errors, thereby reducing them. The process involves two distinct calibration approaches, followed by adjusting the transformation matrix to minimize displacement in the simulated augmented reality.ResultsThe efficacy of this method was assessed through two accuracy evaluations: registration accuracy and augmented reality accuracy. Experimental results showed an average translational error of 2.14 mm and rotational error of 1.06 degrees across axes in both approaches. Additionally, augmented reality accuracy, measured by the overlay regions' ratio, increased to approximately 95%. These findings confirm the enhancement in both calibration and augmented reality accuracy with the proposed method.ConclusionThe study presents a calibration method using simulated augmented reality, which minimizes augmented reality errors. This approach, requiring minimal manual intervention, offers a more robust and precise calibration technique for augmented reality applications in surgical navigation.FALSEsciescopu