Enhance sensitivity of plastic optical fiber sensor by spiral configuration for body temperature applications

In this study, sensors to measure body temperature were made using a macro bending method based on plastic optical fiber. Fiber optic sensors are made to form a spiral configuration on variations in diameter and bend number. The body temperature sensors are mounted on the elastic cloth and placed on the armpit. The light from the LED transmitted into an optical fiber sensor is affected by body temperature, so there is power loss in the sensor. Power loss cause light intensity decreases received by the phototransistor and differential amplifier. The power loss of the sensor and temperature measurement results will be displayed on the computer through the Arduino Uno microcontroller. The range of temperature used is 28°C - 42°C. The best sensor characteristic obtains at the spiral configuration in a diameter of 0 cm with some bending four bends and a range value of 0.421 V, sensitivity of 30.071 mV/°C, and resolution of 0.033°C. Plastic optical fiber is very suitable to be used as body temperature sensors because it can enhance sensitivity.