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수분 섭취 행동에 관여하는 뇌활밑기관에서의 신경아교세포와 신경세포 간 상호 작용 연구
No full textSensory circumventricular organs, subfornical organ, fluid homeostasis, glial cells, purinergic signaling, acid sensing ion channels, resensitizationDoctordCollectio
생리적 신호 기록을 통한 진단 및 폐쇄 루프 신경조절 치료를 위한 이식형 생체 전자 장치
No full textBioelectronics, Implantable devices, Electroceuticals, Biomedical Engineering, Neural InterfaceList of Contents
Abstract i
List of contents iii
List of tables vi
List of figures vii
Ⅰ. Introduction 1
1.1 Bioelectronic implantable devices 1
1.2 Physiological signal recording and closed-loop neuromodulation 8
1.2.1 Mechanical physiological signal recording and closed-loop neuromodulation 9
1.2.2 Thermal physiological signal recording and closed-loop neuromodulation 10
1.2.3 Electrical physiological signal recording and closed-loop neuromodulation 11
1.2.4 Optical physiological signal recording and closed-loop neuromodulation13
1.2.5 Chemical physiological signal recording and closed-loop neuromodulation 14
1.3 Therapeutic implantable closed-loop neuromodulation devices 17
1.4 Requirements for bioelectronic implantable devices 23
1.4.1 Operationality: powering, functionality, communication 27
1.4.2 Integrity: modality, integration, performance29
1.4.3 Adaptability: deformability, implantation, duration 31
1.4.4 Compatibility: animal, consciousness, constraints 34
1.5 Physiological Signals Recording 39
1.5.1 Mechanical biophysiological signals 40
1.5.2 Thermal biophysiological signals 51
1.5.3 Electrical biophysiological signals 60
1.5.4 Optical biophysiological signals 72
1.5.5 Chemical biophysiological signals 84
1.6 Closed-Loop Neuromodulation for Therapy 94
1.6.1 Electrical: electrical stimulation 96
1.6.2 Optical: optogenetics 98
1.6.3 Chemical: drug delivery 101
1.6.4 Multimodal: opto-electric, electro-fluidic, and opto-fluidic 104
Ⅱ. A stealthy neural recorder for the study of behaviour in primates 110
2.1 Introduction 110
2.2 Results 113
2.2.1 Overview of neurobehavioural research using the stealthy neural recorder 113
2.2.2 Flexible deep brain neural probe with a bioresorbable insertion shuttle 117
2.2.3 A body-scale wireless power transfer for naturalistic behaviour 121
2.2.4 Neurobehavioural recording and AI classification of eating behaviour
phases in primates 126
2.3 Methods 131
2.3.1 Design, fabrication and electronic circuits of the stealthy neural recorder 131
2.3.2 Fabrication of the neural probe and electrodes 133
2.3.3 Surface modification of neural electrodes 135
2.3.4 Stamp printing of the sucrose needle 136
2.3.5 Integration, assembly and encapsulation of the stealthy neural recorder 139
2.3.6 Wireless communication, device function and system operation 142
2.3.7 In vitro test 144
2.3.8 Noise immunity test under wireless power transmission 144
2.3.9 FEA for mechanical characterization of the neural probe 145
2.3.10 Dynamic mechanical analysis for the transient mechanics of the
sucrose-coated neural probe 148
2.3.11 Electrochemical impedance spectroscopy (EIS) of 3D nanoporous
electrodes 148
2.3.12 Wireless power transfer system coupled with repeater coil 148
2.3.13 Electromagnetic simulation of wireless power transfer 149
2.3.14 Electromagnetic characterization of coils depending on the implant
environment 152
2.3.15 Surgical implantation 152
2.3.16 Phases of eating behaviour 155
2.3.17 Neurobehavioural signal recording of eating behaviour in NHPs 158
2.3.18 Neurobehavioural signal analysis 161
2.3.19 Neural spike analysis 161
2.3.20 Eating behaviour classification using AI164
2.3.21 Animals 164
2.3.22 Surgical procedures 164
2.3.23 MRI 165
2.3.23 Tissue processing and histological analysis 166
2.4 Discussion 167
2.5 Supplementary information 168
Ⅲ. Artificial baroreflexer for homeostatic regulation of blood pressure in
hypertension 195
3.1 Introduction 195
3.2 Results 201
3.2.1 Design of micro-bump electrode with bioadhesive and in-vivo test 201
3.2.2 Blood pressure, temperature and pulse oximeter sensor 213
3.2.3 Wireless, battery-free, and fully implantable device 219
3.3 Discussion 232
Ⅳ. Advances, challenges and future directions on implantable devices 234
4.1 Engineering challenges 234
4.1.1 Water-resistance and biocompatibility 234
4.1.2 Invasiveness 234
4.1.3 Mechanical mismatch 235
4.1.4 Integrated circuit (IC) 236
4.2 Next-visions 237
4.2.1 Flexible and soft IC 238
4.2.2 AI algorithms for implantable device 239
4.2.3 Edge-AI computing 240
4.2.4 Advanced powering methods 241
4.2.5 Biodegradation 242
4.3 Conclusion 243
References 245
국문요약 271DoctordCollectio
G 단백질 결합 수용체 선택성의 공진화적 기반과 G 단백질 결합 수용체 인산화 효소의 구조 변화에 관한 연구
No full textG protein-coupled receptor, GPCR, G protein, G protein-coupled receptor kinase, GRK, selectivity, structureG protein-coupled receptors (GPCRs) are critical for regulating diverse physiological processes, making them prominent targets in drug development. GPCRs transmit signals through G proteins, which subsequently activate intracellular pathways. Despite extensive research, the precise mechanisms underlying GPCR-G protein selectivity and interaction remain poorly understood. In this study, I applied statistical coupling analysis (SCA) to analyze coevolutionary relationships in model GPCRs, such as serotonin (HTR) and dopamine (DAR) receptors, along with their associated Gα proteins. Our findings reveal conserved and coevolved residues in both GPCRs and G proteins contribute to their functional roles. Additionally, I identified specific coevolutionary pairs that may play crucial roles in GPCR-G protein selectivity, offering new insights into the molecular mechanisms governing their interaction. Furthermore, G protein-coupled receptor kinases (GRKs) play an essential role in modulating GPCR signaling by driving receptor phosphorylation, which influences functional selectivity and biased signaling. To better understand the structural dynamics of GRKs, I analyzed 47 GRK structures retrieved from the Protein Data Bank, focusing on the conformational transitions between their open and closed states. By assigning consistent labels to topologically equivalent positions, I characterized both general and subfamily-specific dynamic movements and quantify these transitions through a detailed conformational change score. These findings provide a deeper understanding of the regulatory mechanisms underlying GRK function and their role in GPCR-mediated signaling. Together, this study contributes to the broader understanding of GPCR-G protein and GRK, highlighting the significance of coevolved residues and structural transitions in modulating functions.|G 단백질 결합 수용체는 다양한 생리적 과정을 조절하는 데 중요한 역할을 하며, 이로 인해 약물 개발에서 중요한 표적이 되고 있다. G 단백질 결합 수용체는 G 단백질을 통해 신호를 전달하며, 그 후 G 단백질은 세포 내 경로를 활성화한다. 오랜 기간의 광범위한 연구에도 불구하고, G 단백질 결합 수용체와 G 단백질 사이의 상호작용과 선택성의 정확한 메커니즘에 관한 의문은 여전히 남아있다. 본 연구에서는 세로토닌(HTR) 및 도파민(DAR) 수용체와 이들의 하위 Gα 단백질에서의 공진화적 관계를 분석하기 위해 Statistical coupling analysis 를 적용했다. 본 연구 결과는 G 단백질 결합 수용체와 G 단백질 모두에서 기능적 역할을 할 가능성이 있는 보존된 공진화 잔기들을 보여주고, 두 단백질 사이의 선택성에 중요한 역할을 할 수 있는 특정 공진화 쌍을 확인하였다. 본 연구를 통해 이들 사이의 상호작용을 규명하는 분자적 메커니즘에 대한 새로운 이해를 가능하게 한다. 또한, G 단백질 결합 수용체 인산화효소는 G 단백질 결합 수용체의 인산화를 유도하여 기능적 선택성에 영향을 미치게 되고, 이로써 하위 신호 전달을 조절하는 데 핵심적인 역할을 한다. G 단백질 결합 수용체 인산화효소의 구조적 특성을 더 잘 이해하기 위해, 본 연구에서는 47개의 G 단백질 결합 수용체 인산화 효소의 구조를 분석하고, 열린 상태와 닫힌 상태 사이의 형태 변화를 중심으로 연구를 진행하였다. 위상적으로 동등한 위치에 라벨을 지정하여 서로 다른 아류형에 대한 일반적인 동적 움직임을 찾았으며, 세부적인 형태 변화 점수를 통해 형태 변화를 정량화 했다. 이 결과는 G 단백질 결합 수용체 인산화 효소의 기능의 조절 메커니즘과 효소 매개 신호 전달에서의 역할을 더 깊이 이해하는 데 기여한다. 결론적으로, 본 연구는 G 단백질의 선택성과 G 단백질 결합 수용체 인산화 효소의 구조적 움직임에 관한 정량적 확인에 관해 다양한 방법으로 접근하였고, 이에 G 단백질 결합 수용체의 신호전달에 관한 여러가지 질문에 대한 새로운 통찰을 제공하고 있다.Ⅰ. Introduction 1
1.1 G protein-coupled receptor (GPCR) signaling system 1
1.1.1 Activation and downstream signals 1
1.1.2 Desensitization and biased signaling 5
1.1.3 Emerging interests on GPCR signaling 7
1.2 Structural features: GPCR, G protein and GRK 9
1.2.1 Structural feature: GPCR 9
1.2.2 Structural feature: G protein 11
1.2.3 Structural feature: GRK 13
1.3 Aim and Objectives 15
1.3.1 Overall aim 15
1.3.2 Objectives 15
Ⅱ. Coevolutionary basis of GPCR-G protein selectivity and functionality 16
2.1 Introduction 16
2.2 Materials and methods 19
2.2.1 Multiple sequence alignment (MSA) 19
2.2.2 Statistical coupling analysis (SCA) 19
2.2.3 Sector identification and refinements 24
2.2.4 Inter-protein statistical coupling analysis 26
2.2.5 GPCR-G protein pattern analysis 26
2.2.6 Statistical validation of inter-protein SCA 29
2.2.7 Structure and graphic representation 29
2.2.8 Visualization and statistics 30
2.3 Results 31
2.3.1 Statistical coupling analysis on model GPCRs 31
2.3.2 Shared conserved sectors in GPCRs: Blue 32
2.3.3 Selectivity-related and coevolved sectors: Red 37
2.3.4 Other sectors involved in ligand binding and functional roles 37
2.3.5 Comparison HTR and DAR sectors 42
2.3.6 Functional networks in G protein from recognition to signal transduction 42
2.3.7 Inter-protein coevolution: Between GPCR and G protein 48
2.4 Discussion 56
Ⅲ. Conserved network of conformational changes in GRK 59
3.1 Introduction 59
3.2 Materials and methods 60
3.2.1 GRK common label (GCL) 60
3.2.2 Structure preparation 62
3.2.3 Contact score calculation 62
3.2.4 Visualization 65
3.2.5 Sequence conservation 65
3.3 Results 66
3.3.1 Identification of conserved ionic lock using GCL system 66
3.3.2 GRK state classification 69
3.3.3 Quantitatively measurements of conformational change between states 71
3.3.4 Secondary structure movements are conserved within subfamilies 74
3.3.5 Residue level movement is conserved via evolutionary conserved residues 80
3.3.6 PH domain plays a crucial role in structure changes in GRK2/3 subtypes 87
3.4 Discussion 89
Ⅳ. Conclusion 92
Ⅴ. References 93
Abstract in Korean 100DoctordCollectio
Development of an Autonomous Driving Path-Generation Algorithm for a Crawler-Type Ridge-Forming Robot
Full text linkThe agricultural sector is currently facing problems including a decline in the agricultural population, labor shortages, and an aging population. To solve these problems and increase agricultural productivity, the development and distribution of autonomous agricultural machinery is necessary. Since autonomous agricultural machinery is operated along a pre-defined path, it is essential to generate an autonomous driving path that takes into account the driving and working methods of the agricultural machinery. In this study, an autonomous driving path-generation algorithm for the autonomous operation of a crawler-type ridge-forming robot is proposed. The proposed algorithm defines the field boundary using the geodetic coordinates of the field boundary points and the size of the robot, generates working line segments within the field boundary, and generates three types of waypoints, which constitute an autonomous driving path based on the autonomous driving operating scenario. To verify the proposed algorithm, tests were conducted using four types of field boundary points with different shapes, and the results are presented. As a result of the simulation test, when a ridge was created using the generated autonomous driving path, the area occupied by the ridge in the total field area according to the field types of a rectangle, trapezoid, pentagon, and hexagon was indicated to be 80, 77, 85, and 77%, respectively. © 2025 by the authors.TRUEsciescopu
초전도 LC 회로에 결합된 Cd3As2 나노 와이어 Josephson 접합 소자에서의 탄도 전자 수송
No full textCd3As2 nanowire, Josephson junction, Superconducting LC circuit, Fabry-Perot interference, SuSchrieffer-Heeger chainList of Contents
Abstract
List of contents
List of figures
Ⅰ. Introduction
1.1 Dirac semimetal 1
1.2 Cd3As2-Topological Dirac semimetal 3
1.3 Superconductor 4
1.4 Josephson junction 5
1.5 Superconducting LC circuit 7
1.5.1 Spiral LC circuit 7
1.5.2 Meander LC circuit 9
1.6 S-parameter in RF measurement 10
1.6.1 Wave reflection and transmission 11
1.6.2 Impedance matching 12
1.7 Su-Schrieffer-Heeger chain 13
1.8 Motivation and potential applications 25
Ⅱ. Design and Fabrication
2.1 Cd3As2 nanowire growth 27
2.2 Device design 27
2.3 Device fabrication 29
2.4 Measurement setup 31
Ⅲ. Experimental Results
3.1 Characteristic of Cd3As2 33
3.1.1 Device specifications 33
3.1.2 Conductance oscillation 35
3.1.3 Josephson junction 36
3.2 Superconducting LC circuit coupled to Cd3As2 nanowire 39
3.2.1 Gate tunable amplitude and resonant frequency 40
3.2.2 Sensitive RF measurement of detecting Fabry-Perot interference 43
3.3 Su-Schrieffer-Heeger LC chain 45
Ⅳ. ConclusionMasterdCollectio
Methylazoxymethanol acetate(MAM)를 이용한 조현병 마우스 모델 프로토콜의 비교 검증: 뇌 구조, 신경세포 및 행동학적 특성 분석
No full textSchizophrenia, Methlyazothymethanol acetate(MAM), Reversal learning, Bayesian inference, Q-learningSchizophrenia is a complex neurodevelopmental disorder characterized by positive, negative, and cognitive symptoms. The methylazoxymethanol acetate (MAM) model has emerged as a valuable tool for studying the neurodevelopmental aspects of schizophrenia. This study aimed to validate and compare different MAM administration protocols (10 mg/kg×3, 25 mg/kg, and 26 mg/kg) in mice by examining neuroanatomical, cellular, and behavioral alterations. MAM-treated mice exhibited significant reductions in brain weight and disrupted hemispheric asymmetry, consistent with neuroanatomical findings in schizophrenia patients. Histological analyses revealed reduced parvalbumin-positive interneurons in the prefrontal cortex and altered dendritic morphology in hippocampal CA1 neurons, paralleling post-mortem findings in schizophrenia. Behavioral assessments demonstrated impaired sensorimotor gating and cognitive flexibility, with the 10 mg/kg×3 group showing particularly robust deficits in reversal learning tasks. Our findings validate the MAM mouse model's ability to recapitulate key anatomical and behavioral features of schizophrenia, with different administration protocols producing distinct phenotypes. This study provides a comprehensive comparison of MAM protocols and establishes their utility for investigating specific aspects of schizophrenia pathophysiology.
Keywords: Schizophrenia, Methylazoxymethanol acetate (MAM), Reversal learning, Bayesian inference, Q- learning| 조현병은 전 세계 인구의 약 0.32%가 앓고 있는 심각한 신경 발달 장애로 환각, 망상과 같은 양성 증상과 감정 표현 감소, 사회적 위축과 같은 음성 증상, 그리고 인지 기능 저하를 보인다. 본 논문은 조현병의 신경 발달학적 동물 모델인 Methylazoxymethanol acetate (MAM)을 주사하여 유도하는 마우스 모델의 프로토콜을 검증하고 비교 분석을 다룬다. 본래 rat에서 시작한 연구로 임신 날짜와 투여량을 조절하는 것이 현 모델의 연구 동향이다. 10 mg/kg의 MAM을 임신 15, 16, 17일 차에 한 번씩 주사하는 방식과 25 또는 26 mg/kg을 임신 16일 차에 한 번 주사하는 프로토콜이 있으며 각각의 그룹이 해부학적으로 어떤 차이가 있는지 밝힌다. 더 나아가 인지에 차이가 있는지 확인하기 위해 Prepulse Inhibition (PPI) 실험과 lever press를 이용한 두 종류의 reversal learning을 수행한다.
MAM 처치 그룹에서 대조군 대비 유의미한 뇌 무게 감소를 확인했으며 정상적으로 나타나는 좌우 반구의 비대칭성이 소실되었다. 전전두엽과 해마에서 파브알부민 세포의 감소를 확인하였으며 이는 조현병 환자의 연구 결과와 일치한다. 골지 염색을 통해 해마 CA1 영역의 피라미달 신경세포에서 수상돌기 형태 변화를 관찰함으로써 3차 가지의 복잡도가 현저히 감소함을 확인하였다.
행동 실험에서는 감각 운동 게이팅(sensorimotor gating) 장애와 인지적 유연성의 저하가 관찰되었다. 통계적 유의를 판단할 수 있는 표본을 가진 10 mg/kg 3회 투여 그룹에서 위치와 확률 기반의 역전 학습 과제 수행 시 대조군과 다른 행동 전략을 취함을 밝혀냈다. 위치 기반의 역전 학습에서는 베이지안 계산을 적용하여 매 시도에서 어떤 전략을 취했는지 분석함으로써 승-유지 (win-stay) 전략을 대조군에 비해 적게 시도함을 확인했다. 확률 기반의 과제에서는 강화학습 중 하나인 Q-learning 모델을 사용하여 파라미터를 확인한 결과, 낮은 베타 값과 높은 델타 값을 확인하였고 이는 무작위적 탐색 전략과 보속성 행동을 취함을 시사한다.
본 연구는 MAM 마우스 모델이 조현병의 주요 해부학적, 세포학적, 행동학적 특징을 재현함을 확인하였으며, 각기 다른 투여 프로토콜이 특징적인 표현형을 유도함을 밝혔다. 이는 조현병의 병태생리 연구와 치료제 개발을 위한 전임상 연구에 있어 MAM 모델의 유용성을 입증하는 결과이다.Ⅰ. INTRODUCTION 1
Ⅱ. Materials and Methods 6
2.1 Animal 6
2.2 MAM administration protocol 6
2.3 Tissue preparation and histological analysis 8
2.4 Neuroanatomical analysis 8
2.5 Fluorescent immunohistochemistry 9
2.6 Golgi-Cox staining 10
2.7 Measurement of brain weights 11
2.8 Diet 12
2.9 Behavioral experiments 12
2.9.1 Prepulse inhibition (PPI) 12
2.9.2 Apparatus 14
2.9.3 Location based reversal learning (LRL) 15
2.9.4 Probabilistic reversal learning (PRL) 18
Ⅲ. Results and Discussions 22
3.1 Reduction in Brain Weights and Disruption of Hemispheric Asymmetry in MAM
Group 22
3.2 Morphological alterations in anterior cingulate cortex and hippocampus of MAM
groups 23
3.3 PV Expression in MAM Groups 27
3.4 Acoustic Startle Response and Prepulse Inhibition (PPI) 29
3.5 Location-Based Reversal Learning 32
3.6 Probabilistic Reversal Learning 34
Ⅳ. Discussion 36
Ⅴ. Conclusions 41MasterdCollectio
ALD 시스템 기반 ZnO TFT 연구
No full textZnO TFT, channel thickness, annealing time, Dielectric Post treatment, Stacked ZnO TFT박막 트랜지스터(TFT)의 성능 향상에 대한 연구는 고해상도 디스플레이, 유연 전자기기, 집적 회로 등 차세대 전자기기의 요구에 따라 지속적으로 진행되고 있다. IGZO가 발견된 이후, 산화물 반도체는 높은 이동도, 광학적 투명성, 저온 공정 호환성 등 우수한 전기적 특성으로 인해 큰 주목을 받고 있다. 초기에는 스퍼터링 기술이 산화물 TFT 제조에 주로 사용되었으나, 원자층 증착(ALD)이 우수한 박막 균일성, 정밀한 두께 제어, 저온 공정 호환성을 제공하며 더욱 유망한 대안으로 떠오르고 있다. 산화물 재료 중에서도 ZnO는 높은 전자 이동도와 간단한 조성을 갖춘 채널 재료로, 저온 공정이 요구되는 응용 분야에 이상적인 후보로 평가받고 있다. 본 연구에서는 ALD로 증착된 ZnO를 이용한 TFT의 전기적 성능을 채널 두께와 어닐링 조건에 따라 체계적으로 조사하였다. 또한, 뉴로모픽 소자나 메모리 소자에 적용 가능한 수직 적층형 TFT 설계를 위해 절연 물질의 형성 방법도 함께 연구하였다. 이동도, 임계 전압(Vth), 서브스레숄드 스윙(SS), 히스테리시스를 포함한 주요 성능 지표를 분석하여 이러한 매개변수의 영향을 평가하였다. 연구 결과, 디바이스 성능은 주로 산소 공공(Vo) 농도와 결정성의 약간의 향상에 의해 영향을 받는 것으로 나타났으며, 이는 XRD, AFM, XPS 분석을 통해 확인되었다. 특히, 180°C에서 1시간 동안 어닐링한 30nm ZnO 채널에서 최적의 이동도, 안정성, 캐리어 농도를 보이며 최적화된 성능이 확인되었다. 또한, ZnO-HfO2 인터페이스의 특성을 조사하기 위해 HfO2 게이트 유전체층에 O2 플라즈마, 오존 노출, 열 어닐링과 같은 후처리 공정을 적용하였다. 이러한 후처리 방법은 트랩 밀도(Dit)를 감소시키고 유전율을 향상시켜 인터페이스 품질을 개선하였으며, 이는 정전 용량 증가와 전기적 안정성 향상으로 이어졌다. 특히, 오존 노출과 O2플라즈마 처리는 산소 관련 결함을 감소시키고 전체 디바이스 성능을 향상시키는 데 매우 효과적인 것으로 나타났다. 마지막으로, 3D 통합 기술을 진전시키기 위한 중요한 단계로서 수직 적층 ZnO-HfO2 TFT 구조의 가능성을 탐구하였다. 전체 공정의 열 안정성을 고려하여 200°C 이하의 온도에서 상부 층 구조를 형성하는 것이 적합하다는 것이 확인되었다. 에폭시 수지 기반 폴리머를 스핀 코팅하여 인터레이어 물질로 사용하는 것이 가장 효과적인 것으로 나타났다. 해당 폴리머는 ZnO TFT 위에 코팅되었거나, 해당 폴리머 위에 ZnO TFT가 제작된 경우 모두에서 on-current와 임계 전압(Vth)의 저하가 미미한 것으로 확인되었다. 이는 해당 폴리머가 ZnO-HfO2 디바이스의 저온 적층을 가능하게 하는 인터레이어 물질로 적합함을 입증하였다. 이러한 결과는 수직 적층 디바이스 연구의 견고한 기초를 마련하였으며, 뉴로모픽 소자나 메모리 소자와 같은 응용 분야에서 중요한 가능성을 제시하였다.
핵심어: ZnO 두께, 어닐링 시간, 절연체 후처리, 적층 구조|Research on improving thin-film transistor (TFT) performance continues to progress, driven by the demands of next-generation electronic devices, including high-resolution displays, flexible electronics, and integrated circuits. Since the discovery of IGZO, oxide semiconductors have attracted significant attention due to their superior electrical properties, such as high mobility, optical transparency, and low-temperature compatibility. While sputtering techniques were initially dominant in oxide TFT fabrication, atomic layer deposition (ALD) has emerged as a more promising alternative, offering excellent film uniformity, precise thickness control, and compatibility with low-temperature processes. Among oxide materials, ZnO is one of important candidates due to its high electron mobility and simple composition for the channel material of TFT, making it ideal for applications requiring low thermal budgets. This study systematically investigated the electrical performance of TFT employing ALD-deposited ZnO by varying the channel thickness and annealing conditions. Additionally, the formation of insulating material on TFT was studied for vertical stacked design of TFTs which can be applied to neuromorphic hardware or new memory concepts. Critical performance metrics, including mobility, threshold voltage (Vth), subthreshold swing (SS), and hysteresis, were analyzed to determine the influence of these parameters. The results revealed that device performance was primarily affected by oxygen vacancy (Vo) concentration and minor improvements in crystallinity, as confirmed through XRD, AFM, and XPS analysis. Specifically, optimized performance was achieved with a 30 nm ZnO channel annealed at 180°C for 1 hour, demonstrating optimal values of mobility, stability, and carrier concentration. Furthermore, this study applied O2 plasma, ozone exposure, and thermal annealing as post- treatment processes to the HfO2 gate dielectric layer to investigate their effects on the ZnO-HfO2 interface. These post-treatment methods improved interface quality by reducing trap density (Dit) and enhancing the dielectric constant, resulting in increased capacitance and improved electrical stability. Among the techniques, ozone exposure and O2 plasma treatments were particularly effective in reducing oxygen-related defects and enhancing overall device performance. Finally, the feasibility of vertically stacked ZnO-HfO2 TFT structures, a critical step for advancing 3D integration technologies, was explored. Considering thermal budget of full process, it is suitable to form upper layer structures below 200°C. Spin coating of epoxy resin based polymer was identified as the most effective interlayer material. The epoxy resin-based polymer showed negligible degradation in on-current and threshold voltage, both when coated on ZnO TFTs and when ZnO TFTs were fabricated on top. This confirmed its viability as an interlayer material, enabling low-temperature stacking of ZnO-HfO2 devices. These findings establish a solid foundation for vertically stacked devices, presenting significant potential for applications in neuromorphic systems and memory devices. Keywords: ZnO TFT, channel thickness, annealing time, Dielectric Post treatment, Stacked ZnO TFTⅠ. Introduction 1
1.1 Overview 1
1.2 Previous work 3
Ⅱ. Backgrounds 5
2.1 Overview of Thin-Film Transistors (TFTs) 5
2.2 Development of Amorphous Oxide Semiconductors 7
2.3 Advancements in Thin-Film Deposition: Atomic Layer Deposition (ALD) 9
2.4 Post-Treatment Methods for Oxide Dielectrics 9
2.5 Stacked TFTs and M3D Integration Potential 11
Ⅲ. Experiment details 13
3.1 Device fabrication 13
3.2 Experimental setup 16
Ⅳ. Result and Discussion 17
4.1 ZnO Channel Thickness and Annealing Time 17
4.1.1 Correlation Between Thickness, Annealing Time, and Device Performance · 18
4.1.2 Thin Film Characterization via AFM, XRD, and XPS 26
4.2 Performance Differences According to Post-Treatment for HfO₂ 31
4.2.1 Dielectric Constant and breakdown voltage on MIM structure 31
4.2.2 capacitance change on MIS structure 33
4.3 Stacked HfO-ZnO TFT structure 35
4.3.1 Thin film deposition interlayer materials 36
4.3.2 Polymer coating interlayer materials 37
4.3.3 ZnO TFT performance on polymer coating materials 39
Ⅴ. Conclusion. 41MasterdCollectio
Leveraging Dynamic Bond Cleavage Reaction for Functional and Sustainable Applications
No full textElectrically mediated, Mechanically-meditated, Small molecules-meditated, Functional materials, Sustainable polymer, Dynamic bond cleavageⅠ. Introduction 1
1.1 Bond Cleavage Chemistry 1
1.2 Clip Chemistry 1
1.2.1 Examples of Clip Chemistry (Stoichiometric Clip Reaction) 2
1.2.2 Examples of Clip Chemistry (Catalytic Clip Reaction) 3
1.2.3 Examples of Clip Chemistry (Electron Transfer Mediated Clip Reaction) 4
1.2.4 Examples of Clip Chemistry (Light-Mediated Clip Reaction) 5
1.2.5 Examples of Clip Chemistry (Thermally Mediated Clip Reaction) 6
1.2.5 Examples of Clip Chemistry (Force- Mediated Clip Reaction) 7
1.3 Dynamic Covalent Polymer Network 8
1.4 Mechanism of Dynamic Covalent Polymer Network 9
1.5 Vitrimer-like Materials (Dissociative bond) 10
1.5.1 Siloxane Silanol Exchange Reaction 10
1.5.2 Disulfide Exchange Reaction 11
1.5.3 Carboxylate Transesterification 12
1.6 Vitrimer Materials (Associative Bond) 12
1.6.1 Vinylogous Urethane (Transamination) 12
1.6.2 Ester Bond (Transesterification) 12
1.6.3 Oxim Bond (Transcarbamoylation) 13
1.7 Recycling Methods 14
1.7.1 Mechanical Recycling 14
1.7.2 Chemical Recycling 15
1.8 Close-loop Chemical Recycling 17
1.8.1 Polyesters Based on Lactones 17
1.8.2 Carbamate Bond 19
1.8.3 Schiff Base 20
1.8.4 Carbonate Bond 21
1.9 Reference 23
IⅠ. Self-Powered Patches with Precision Guest Release Enabled by Electro-Mechanochemical Gating of Metal–Phenolic Nanocages 28
2.1 Introduction 28
2.2 Results and Discussion 31
2.2.1 Synthesis and Characterization 31
2.2.2 Voltage-meditated Cleavage Reaction and Mechanism 33
2.2.3 Ultrasound-meditated Cleavage Reaction 36
2.2.4 Applications 37
2.3 Conclusion 41
2.4 Experimental Section 42
2.4.1 Materials 42
2.4.2 Synthesis of MSN-0 42
2.4.3 Typical Preparation of TA-FeⅢ/MSN 43
2.4.4 Preparation of TFM-PAAm Hydrogel 43
2.4.5 Preparation of TFM-STENG 44
2.4.6 Characterization 44
2.5 Reference 46
2.6 Supporting Information 57
IⅠI. Supramolecular Engineering of Recyclable, Adaptive Polymer Composites for High-Performance Sensory Applications 68
3.1 Introduction 68
3.2 Results and Discussion 72
3.2.1 Synthesis and Characterization 72
3.2.2 Model Reaction Study 79
3.2.3 Effect of Cross-linking Density on Electrothermal Effect 80
3.2.4 Effect of Cross-linking Density on photothermal Effect 83
3.2.5 Effect of Cross-linking Density on Sensory Behaviors 84
3.2.6 Chemical and Mechanical Recycling 86
3.3 Conclusion 89
3.4 Experimental Section 90
3.4.1 Materials 90
3.4.2 Synthesis of poly(BMA-co-AAEMA), PBA 90
3.4.3 Synthesis of Covalent Polymer/SWCNT Composites (CPC4-24 %) 91
3.4.4 Swelling Ratio Test of DPC4-24% and DPC4-2.4% 92
3.4.5 Gel Fraction Test of DPC4-24% and DPC4-2.4% 92
3.4.6 Synthesis of mAA-Bu and mAA-Bz 93
3.4.7 Bond Exchange Reactions from mAA-Bz to mAA-Bu 93
3.4.8 Mechanical recycling of DPC4-24% 93
3.4.9 Chemical recycling of DPC4-24% 94
3.4.10 Characterization 94
3.5 Reference 97
3.6 Supporting Information 113DoctordCollectio
임상 수준의 개인 맞춤형 헬스케어를 위한 웨어러블 피부 패치
No full textSkin-interfaced electronics, System-level, Multiplexed monitoring, Responsive drug delivery, Clinical diagnostic toolThe primary objective of this dissertation is to explore the development and application of advanced wearable biomedical devices designed for real-time biosensing and controlled drug delivery, as well as the diagnosis of specific medical conditions such as cardiovascular diseases and vocal cord disorders. These systems leverage key advanced functionalities, including multiplexed monitoring, closed-loop operations, novel biomarker detection, and AI-based classification. The research aims to offer new opportunities for personalized healthcare by integrating these cutting-edge technologies into wearable platforms. The first part of the research introduces a wireless, folded multi-modal device (fMMD) that incorporates a mechanically isolated heterogeneous structure capable of simultaneous biosensing and drug delivery. The proposed system monitors quantitative information on hemodynamic and cardiovascular health using electrical and optical modalities, combined with a force-electrically driven micropump for drug delivery. The device integrates a flexible printed circuit board with functionally sectioned islands connected by serpentine interconnects, ensuring robustness against deformation and stretchability on the skin. The fMMD achieves real-time monitoring and on-demand drug delivery through wireless transmission, establishing a new platform for closed-loop intelligent healthcare that can be applied to various conditions, such as blood glucose monitoring, pain management, and chronic disease treatment. The second part presents the wireless, skin-interfaced glottal vibratory monitoring system (EGG-Tie) for diagnosing vocal cord disorders. The EGG-Tie system simultaneously monitors electroglottographic (EGG) signals and vocal measurements using electrodes placed on either side of the thyroid cartilage. The system features a bi-stable structure for robust signal acquisition during movement and a polyurethane-based 3D dome electrode filled with Field's metal to enhance signal performance. The EGG-Tie system enables real-time analysis of vocal parameters, including fundamental frequency, contact quotient, and variability index, allowing for the classification of vocal cord disorders. The device demonstrates comparable performance to state-of-the-art clinical technologies, providing an effective diagnostic tool for real-world medical applications. Consequently, these studies contribute to the advancement of wearable biomedical systems by combining real-time biosensing, closed-loop operation, and AI-driven diagnostics into a single platform. This research highlights the potential for wearable devices to transform personalized healthcare through more efficient and precise monitoring, treatment, and diagnosis. Keywords: Skin-interfaced electronics, System-level, Multiplexed monitoring, Responsive drug delivery, Clinical diagnostic tool|본 논문의 주요 목표는 실시간 생체신호 감지 및 제어된 약물 전달을 위해 설계된 고급 웨어러블 생체의료 기기의 개발 및 응용을 탐구하는 데 있다. 또한, 심혈관 질환 및 성대 질환과 같은 특정 의학적 상태의 진단에도 중점을 둔다. 이러한 시스템은 다중 모니터링(multiplexed monitoring), 폐루프 작동(closed-loop operation), 새로운 바이오마커 탐지(novel biomarker detection), AI 기반 분류(AI-based classification)와 같은 주요 고급 기능을 활용하여 웨어러블 플랫폼에 첨단 기술을 통합함으로써 맞춤형 헬스케어에 새로운 기회를 제공하는 것을 목표로 한다. 첫 번째 연구는 무선 접힘형 다중 모달 기기(fMMD)를 소개한다. 이 기기는 생체신호 감지와 약물 전달이 서로 피드백을 주고 받으면서 동시에 동작 가능한 기능적 요소를 가지고, 기계적으로 분리된 이질 구조를 통합하고 있다. 제안된 시스템은 전기적 및 광학적 모달리티를 기반으로 심혈관 건강 상태에 대한 정량적 정보를 모니터링하며, 약물 전달을 위해 힘-전기(force-electrical) 구동 미세펌프를 결합한다. 이 장치는 기능적으로 구분된 섬들이 구불구불한 연결부로 연결된 유연한 인쇄회로기판(FPCB)을 통합하여 피부에 부착된 상태에서도 변형에 강하고 신축성을 유지할 수 있다. fMMD는 무선 전송을 통해 실시간 모니터링 및 필요에 따른 약물 전달을 가능하게 하며, 이는 혈당 모니터링, 통증 관리, 만성 질환 치료와 같은 다양한 의료 조건에 적용될 수 있는 새로운 폐루프 지능형 헬스케어 플랫폼을 제공한다. 두 번째 연구는 성대 질환 진단을 위한 무선 피부 인터페이스 성대 진동 모니터링 시스템인 EGG-Tie를 제안한다. EGG-Tie 시스템은 갑상연골 양측에 배치된 전극을 사용하여 전기성문도(EGG) 신호와 음성 신호를 동시에 모니터링한다. 이 시스템은 신호 수집 중 움직임에도 견고한 신호 획득을 보장하는 이중 안정 구조를 특징으로 하며, 폴리우레탄 기반 3D 돔 구조의 전극 소재로 생체 적합성 액체 금속인 Field’s metal을 활용하여 신호 성능을 향상시킨다. 또한 EGG-Tie 시스템은 지속적 모음 발성 및 연속된 음성 데이터를 통해 실시간으로 기본 주파수(fundamental frequency), 접촉 지수(contact quotient), 변동 지수(variability index), 주파수 응답과 같은 주요 음성 매개변수를 분석하여 성대 질환을 분류할 수 있다. 이 장치는 임상에서 사용되는 최신 기술과 유사한 성능을 입증하며 실제 의료 응용에 효과적인 진단 도구를 제공한다. 결론적으로, 이러한 연구들은 실시간 생체신호 감지, 폐루프 동작, AI 기반 진단을 단일 플랫폼에 통합함으로써 웨어러블 생체의료 시스템의 발전에 기여한다. 본 연구는 웨어러블 기기가 맞춤형 헬스케어를 위한 보다 효율적이고 정밀한 모니터링, 치료 및 진단을 통해 의료 분야에 혁신을 가져올 잠재력을 강조한다.List of Contents
Abstract i
List of contents iii
List of tables vi
List of figures vii
Ⅰ. Introduction
1.1 Wearable electronics 1
1.2 Fully integrated wearable biosensing devices 2
1.2.1 Physical monitoring 2
1.2.2 Cardiovascular monitoring 3
1.2.3 Brain activity monitoring 4
1.2.4 Voice monitoring 5
1.2.5 Mental health monitoring 7
1.2.6 Biochemical-related disease monitoring 8
1.3 Responsive drug delivery devices 9
1.3.1 Drug delivery in response to physiological, electrophysiological signals 10
1.3.2 Drug delivery in response to biochemical signals 10
1.4 Advanced functionalities of wearable medical device 11
1.4.1 Multiplexed monitoring 11
1.4.2 Closed-loop operation 12
1.4.3 Novel biomarker detection 13
1.4.4 AI-based diagnosis and treatment 13
1.5 Research objectives and chapter outlines 14
Ⅱ. Vialess heterogeneous skin patch for multimodal monitoring and stimulation
2.1 Introduction 16
2.2 Results 18
2.2.1 Design and system architecture of fMMD 18
2.2.2 Mechanical properties of fMMD 25
2.2.3 Design and operation of on-demand drug delivering modality 30
2.2.4 PPG monitoring based on flexible PDMS waveguides 40
2.2.5 Real-time multiplexed monitoring and closed-loop operation 48
2.3 Methods 53
2.3.1 Circuit design for the fMMD 53
2.3.2 Fabrication process of chemical module with peristaltic pump 53
2.3.3 Fabrication and assembly of microneedle array 54
2.3.4 Fluid flow rate measurement 55
2.3.5 Fabrication and assembly of optical module for PPG monitoring 56
2.3.6 Finite Element Analysis of fMMD’s mechanical stability 56
2.3.7 Finite Element Analysis of fMMD’s fluidic stability 57
2.3.8 Finite Element Analysis of foldable fMMD’s waveguiding 57
2.3.9 Data analysis and algorithms for multiplexed measurement and closed
loop operation 60
2.4 Discussion 60
Ⅲ. A wearable glottal vibratory monitoring system for medical diagnosis of vocal cord
disorders
3.1 Introduction 62
3.2 Results 63
3.2.1 Design and system architecture of EGG-Tie 63
3.2.2 Advanced use cases in phonation analysis 82
3.2.3 Deep learning classification of vocal cord disorders 97
3.3 Methods 102
3.3.1 Electronic circuit design of the EGG-Tie system 102
3.3.2 Fabrication of 3D dome-shaped voice collecting port and electrode 103
3.3.3 Assembly and encapsulation of the EGG-Tie system 103
3.3.4 Wireless communication and system operation 104
3.3.5 DMA measurement of bi-stable structure 104
3.3.6 Skin impedance measurement 104
3.3.7 Wireless charging system 105
3.3.8 Signal processing for sustained vowel phonation 105
3.3.9 Statistical analysis of variability indices 106
3.3.10 Signal processing for contact quotient 107
3.3.11 Classification of vocal cord disorders 107
3.4 Discussion 108
Ⅳ. Conclusion and future prospects 110
References 115
국문요약 129DoctordCollectio