Flexible 화학 센서를 위한 3차원의 전도성 고분자 와이어 Arrays

Abstract

Flexible chemical sensor array have been widely studied for environmental monitoring, bio-medical application because of their advantages of wearable, attachable and implantable characteristics. In the chemical sensors, the core is sensing body which reacts with analytes and converts to electric signal. Among the sensing materials, conducting polymers are known to show short response time, room temperature operation, excellent formability and good conductivity. In these reasons, the conducting polymers are adaptable to sensing materials for flexible chemical sensors. To enhance the flexibility in chemical sensor array, there are two strategies that are plastic substrates and 3D conducting polymer wire array. The strategies are already applied to flexible electronics. The plastic substrates have already embodied for the flexible chemical sensors, but the construction of 3D sensing material is still a challenge in conventional methods such as soft-lithography or direct writing techniques. In this thesis, we demonstrated a novel strategy to achieve 3D PEDOT

PSS wire array sensor on plastic substrates for flexible chemical sensor using direct writing of extensional deformed meniscus based on fountain pen. The diameter of wires could be controlled by pulling speed. We discovered the relationships the diameter with pulling speed through “coffee ring effect”. The model was answered to previous result. Using two point probe method, we demonstrated that the 3D PEDOT

PSS wire sensor was exhibited linear dependence of sensitivity on acetone concentration and the surface area to volume ratio of wires. We also revealed the height effect of the 3D wire flexible chemical sensor on sensitivity. As increase of height, the swelling was more distinguished effect than the surface to volume ratio. Finally, we demonstrated the 3D PEDOT

PSS wire array on the PDMS plastic substrate. The 3D configuration of PEDOT

PSS wire could be observed by SEM. Being based on these results, we suggest new design of flexible chemical sensors for applications that range from real-time pollution regulation to highly portable biological- and chemical-threat detectors.