Abstract
This paper reports a novel extrinsic Fabry-Perot interferometer (EFPI)-based fiber optic sensor for force measurement. The prototype force sensor consists of two EFPIs mounted on a stainless-steel rectangular frame. The primary sensing element, i.e., the first EFPI, is formed between the endface of a horizontally placed optical fiber and a stainless-steel buckled beam. The second EFPI, fashioned between a longitudinally placed optical fiber and a silver-coated glass beam, is arranged to demonstrate the amplification mechanism of the buckled beam structure. When the sensor is subjected to a tension force, the pre-buckled beam will deflect backward, resulting in a longitudinal/axial displacement of the pre-buckled beam. The axial displacement is further transferred and amplified to a horizontal/vertical deflection at the middle of the buckled beam, leading to a relatively significant change in the Fabry-Perot cavity length. A force sensitivity of 796 nm/ {N} (change in cavity length/Newton) is achieved with a low-temperature dependence of 0.005 {N} /°C. The stability of the sensor is also investigated with a standard deviation of ± 5 nm, corresponding to a measurement resolution of ±0.0064 N. A simulation is conducted to study the axial displacement and stress distribution of the sensor when it is subjected to a tension load of 250 N. It is demonstrated that the maximum stress of the sensor is tremendously reduced attributed to the buckled design, enabling a long service life cycle of the force sensor. The robust and simple-to-manufacture force sensor has great potential in structural health monitoring, robotics control, and oil/ gas refining systems.
Recommended Citation
Y. Tang et al., "Optical Interferometric Force Sensor based on a Buckled Beam," IEEE Sensors Journal, vol. 22, no. 2, pp. 1301 - 1308, Institute of Electrical and Electronics Engineers, Jan 2022.
The definitive version is available at https://doi.org/10.1109/JSEN.2021.3130615
Department(s)
Electrical and Computer Engineering
Keywords and Phrases
Buckled beam; cavity length change; EFPI; optical fiber force sensor
International Standard Serial Number (ISSN)
1558-1748; 1530-437X
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2023 Institute of Electrical and Electronics Engineers, All rights reserved.
Publication Date
15 Jan 2022
