광섬유 열 수축 슬리브를 활용한 FBG 굽힘 센서 개발

Instead of a single fiber Bragg grating (FBG) sensor, a new type of optical-fiber bending sensor was proposed through the geometrical combination of three strands of optical fiber lines of a fiber Bragg grating (FBG) sensor. The three strands of the FBG sensor optical fiber lines must be positioned at 120° intervals from one another in the circumferential direction to improve the performance of the proposed optical-fiber bending sensor. The sensor was manufactured through delicate manual work to fabricate the geometrical structure; however, the fabrication was very difficult because the possibility of error was high. Therefore, in this study, a new manufacturing method using a heat-shrink sleeve was developed to solve the problems of the conventional manufacturing method. In addition, a bending sensor was fabricated using a heat-shrink sleeve and a bending sensor manufactured based on the conventional method. Cantilever bending experimental tests were performed to compare the performance of the two types of optical-fiber bending sensors. It was confirmed that the performance of the bending sensor using the proposed heat-shrink sleeve was more stable.