1. INTRODUCTION 1 1.1 Background 1 1.1.1 Biomedical microrobots 1 1.1.2 In vitro neural network 6 1.2 Research trend or related research works 12 1.2.1 Microrobots for cell delivery 12 1.2.2 Engineered networks for structural and functional connection 18 1.2.3 Multielectrode arrays (MEAs) 21 1.3 Aims of the current study 26 2. NANO-PATTERNED SU-8 SURFACE USING NANOSPHERE-LITHOGRAPHY FOR ENHANCED NEURONAL CELL GROWTH 27 2.1 Introduction 27 2.2 Materials and methods 30 2.3 Results and discussion 35 2.4 Conclusion 48 3. AN SU-8-BASED MICROPROBE WITH A NANOSTRUCTURED SURFACE ENHANCES NEURONAL CELL ATTACHMENT AND GROWTH 49 3.1 Introduction 49 3.2 Materials and methods 52 3.3 Results and discussion 56 3.4 Conclusion 63 4. A MAGNETICALLY ACTUATED MICROROBOT FOR TARGETED NEURAL CELL DELIVERY AND SELECTIVE CONNECTION OF NEURAL NETWORKS 64 4.1 Introduction 64 4.2 Results 67 4.3 Discussion 92 4.4 Materials and methods 96 5. A MAGNETICALLY DRIVEN NEUROSPHEROID MICROROBOT FOR TARGETED NEURAL CONNECTION 106 5.1 Introduction 106 5.2 Results and discussion 108 5.3 Materials and methods 116 5.4 Conclusion 122 6. CONCLUSIONS 123 6.1 Overall conclusions 123 6.2 Future work 125 6.2.1 Surface engineering with nanostructures and microprobes 125 6.2.2 In vitro neuronal connections using diverse approaches 126 6.2.3 Improvement in neuronal connections ex vivo 127 6.2.4 In vivo application of the magnetic neurospheroid 128 ACKNOWLEDGEMENTS 129 Publication List 132 REFERENCES 135 요 약 문 147 APPENDIX 149 1. Immunocytochemistry (ICC) protocol combined with tissue clearing 149 2. Confocal imaging using LSM 800 151 3. Electrophysiological analysis using Maxwell Biosystems MaxOne 154