Influence of coupling agent’s self-assembly upon performance of polymer coated FBG pressure sensors

Abstract

Based on super-molecule self-assembly and entropy-driven self-assembly mechanisms, the coupling agent was evolved into colloid spheres with average diameter of 2-2. 3 μm on the fiber Bragg grating (FBG) with silicon substrate, and the coupling mechanism among polymer, coupling agent and FBG was analyzed. The polymer coated FBG pressure sensors was capsulated by uniform coupling mode and self-assembly coupling mode of the coupling agent respectively, and their performance parameters were tested. It was shown, adopting the self-assembly coating of coupling agent and with the same other capsulated technologies, that the measuring range of the sensor expanded from 0.6 MPa to 1.6 MPa, the repeated times for coupling failure increased from 54 to 125 times and the pressure sensitivity coefficient enhanced from 1.09 to 2.98. By controlling the diameter of the spheres and the line density, the measuring range and the sensitivity of the FBG pressure sensors can be obviously improved.