A Lossless Fiber Pressure Sensor Based on PDMS
Kai Cui, Hong Yingping, Sui Dandan, Liu Wenyi, Zhang Huixin
Abstract
Fiber optic pressure sensors have been widely used in recent decades. Most of the fiber optic pressure sensors use fiber gratings and Fabry-Perot cavity. However, they have the drawbacks of in achieving distributed sensing. In this paper, a lossless fiber pressure sensor based on a structure composed of two ratios of the polydimethylsiloxane (PDMS) and single-mode fiber is proposed. The PDMS has often been used as a flexible structural material. When the pressure is acting radially on the PDMS, the internal fiber is driven to produce an axial strain of a larger range, and the optical frequency domain reflectometer (OFDR) is used to demodulate the fiber strain. The experimental results prove that the designed sensor has a repeatable response with a sensitivity of 17.519 $\mu \varepsilon $ /N within the range of 20 N (2548 kPa). The minimum pressure resolution and spatial resolution of the sensor can reach values of 0.5 N and 0.5 cm, respectively. Compared to a single ratio PDMS sensor, which has a non-linear response to the pressure, the range is increased by about 1.4 times. Based on the obtained results, the proposed sensor has application prospects in pressure sensors.