Bio-Inspired Stimuli-Responsive Smart Adhesive Systems for Macroscopic/Microscopic Applications = 생체모사 기반 감응형 스마트 접착 시스템 개발 및 응용

다국어 초록 (Multilingual Abstract)

Smart adhesive systems with actively controllable and switchable adhesions on demand in response to external signals such as temperature, light, humidity, electric current have attracted lots of atterntions thanks to their various potential applications in both of macroscopic and microscopic fields including medical patch, skin adhesive, robotics, transport and transfer, wearble device and so on. Many researches for the realization of smart adhesive systems which can be employed to the broad applications have been widely achieved, however it is still required to develop new smart adhesive systems with high-performance and unique adhesive properties containing high adhesive strength, high on/off switching ratio of adhesion, fast response, low preload, excellent durability, etc.
To satisfy the increasing demands for the development a high-performance smart adhesive system, in this thesis, we employed two approaches of the biological mimicry of switchably adherable creatures in nature and the adoption of smart materials. In nature, many creatures having magnificient switchable adhesion systems for their static/dynamic locomotion already exist, such as anisotropic van der Waals force adhesion of gecko, capillary-force adhesion of insects and tree frog, pressure-induced adhesion of octopus. These switchable adhesive systems in nature can be a key to realize newly improved smart adhesive systems by mimicking the adhering mechanism and structures of the creatures. Besides, the adoption of smart materials in smart adhesive systems, where their physical and chemical properties can be significantly changeable by the external stimuli such as thermal, optical, elctrical, acidic, and chemical changes, can give a capability of on-demand control of adhesion to the smart adhesive systems.
In this thesis, we introduce the novel platform of high-performance smart adhesive systems with superior adhesive properties, realized by the combination of biological inspiration and smart materials. First in Chapter 1, a definition and various types of smart adhesive systems with the recent research trends, switchable adhesion in nature, adhesive systems inspired by nature, and smart materials for the smart adhesive systems, following a summary of key components in the smart adhesive systems for the practical applications, are briefly introduced. In Chapter 2, an octopus-inspired thermo-responsive smart adhesive pad whose adhesive properties can be controlled on demand by external heat is demonstrated, realized via the combination of thermo-responsive hydrogel, pNIPAM, and microcavity-structured PDMS elastomer. The thermo-responsive smart adhesive pad shows the outstanding adhesive performance with extremely high adhesive strength and on/off ratio of adhesion without any preload and consequently it can be applied to transfer printing of sensitive and fragile semiconducting micro/nanomembranes as microscopic applications. In Chapter 3, an octopus-inspired light-responsive smart adhesive pad with actively controllable adhesion on demand in response to external near-infrared light is introduced, fabricated via the rGO/pNIPAM light-responsive hydrogel composite on microcavity-structured PDMS elastomeric support. The light-responsive hydrogel smart adhesive pad exhibits remotely controllable adhesion and fast response time with excellent adhesive strength and on/off ratio of adhesion. This smart adhesive pad is applied to adhesive patch as macroscopic application. In Chapter 4, the summary and future perspective of our smart adhesive systems are described. Our bioinspired smart adhesive systems realized by stimuli-responsive hydrogel actuations on microstructured elastomeric support can suggest a new concept for a high-performance smart adhesive system to be applied to various practical industries.

목차 (Table of Contents)

• Abstract 1
• Contents 4
• List of Figures 5
• List of Tables 11
• Nomenclature 12
• Chapter 1. Introduction 14
• 1.1 Smart adhesive systems 16
• 1.2 Limitation of conventional smart adhesive systems 18
• 1.3 Creatures with switchable adhesion in nature 19
• 1.4 Bio-inspired adhesive systems 21
• 1.5 Smart materials for smart adhesive systems 25
• Chapter 2. Octopus-inspired thermo-responsive smart adhesive pads 27
• 2.1 Introduction 27
• 2.2 Results and Discussion 29
• 2.3 Experimental Details 47
• 2.4 Conclusions 51
• Chapter 3. Octopus-inspired light-responsive smart adhesive pads 52
• 3.1 Introduction 52
• 3.2 Results and Discussion 54
• 3.3 Experimental Details 63
• 3.4 Conclusions 65
• Chapter 4. Summary and Future perspective 66
• References 68
• Appendix A: List of Achievements 75
• Acknowledgements 78