Polydimethylsiloxane-coated Fiber Bragg Grating as a Bend Sensor

The fiber Bragg grating sensor is often demonstrated as a bend sensor. However, the demonstrated sensor in previous studies was limited to low sensitivity, thus reducing the sensing performance. Hence, this work demonstrated the polydimethylsiloxane-coated fiber Bragg grating sensor for sensitivity enhancement. The proposed sensor with a diameter of 5 cm was bent by adjusting the translation stage from 0.1 cm to 0.9 cm distance in forward and backward direction. The results showed that the Bragg wavelength shifted towards the longer wavelength region when the distance decreased. The polydimethylsiloxane-coated fiber Bragg grating sensor shows a sensitivity of 1743000 A.U, 8 times higher than the uncoated fiber Bragg sensor with a sensitivity of 284000 A.U. The presence of the polydimethylsiloxane layer has successfully improved the sensor performance.