전기수력학적 젯 프린팅을 이용한 격자식 크랙 탐지 센서의 위치 추정 알고리즘

Abstract

Recently, as the number of old structures and the collapse of structures frequently occur, the importance of the structural health monitoring (SHM) technology that can reduce the damage is emerging. So, SHM sensors are developed using principles of various fields such as mechanical engineering, chemistry, and electricity to ensure the durability of structures and to increase their precision. The cracks gradually increase in size from the micro cracks. That is why it is important to diagnose micro cracks early. For diagnose micro cracks, the sensor must have excellent precision and sensitivity. If nano structures are used to diagnose the micro crack, it can receive signals down to the smallest detail. So, electrohydrodynamics(EHD) inkjet printing technology is applied for crack detection. In this paper, the crack detection algorithm of micro-electro mechanism systems(MEMS) based grid-type sensor is comprehended for detecting micro cracks using EHD inkjet printing technology. In order to apply the EHD inkjet printing technology, the process variable control is essential. So the optimization of voltage, flow rate and working height was performed for EHD inkjet printing. In addition, flexible conductivity was measured for the application of the curved part and flexible device. The crack location was estimated using the tendency of the resistance change ratio of the cracked circuit. The crack detection algorithm was verified through three-dimensional graphs. In addition, a crack estimation program was created for intuitive crack location, which was compared for 10X10 and 20X20 samples. By increasing the grid scale, it was possible to construct a detailed grid in the PI film used as the substrate of the sample, thereby increasing the accuracy of crack detection based on the resistance change.