Quadri-directional optical bending sensor using side-emitting POF integrated with wearable device technology in smart glove

Purpose It is important to monitor wrist four direction movements (flexion, extension, adduction and abduction) for hand healthcare, wrist rehabilitation and upper limb exercise, and so on. The purpose of this study is to develop a quadri-directional optical bending sensor that integrated wearable device technology in a smart glove to detect wrist four direction movements. Design/methodology/approach The quadri-directional optical bending sensor was designed with a microcontroller board, a Bluetooth wireless module, a side-emitting polymeric optical fibre (POF), an infrared light emitting diode and four phototransistors. A linear equation was deduced to calculate bending angle from detecting sensor value of Arduino microcontroller. The bending angle values could be seen by the smartphone screen, so the system has a good human–machine interface function. Findings The light emission by macro-bending of the side-emitting POFs that the transmittance of the outer side is greater than the inner. The bending POFs lateral emission phenomenon integrated with phototransistors on the edge is suitable for the development of bending sensors. Originality/value This study is to develop a novel quadri-directional optical bending sensor to replace two bi-direction sensors or four uni-direction sensors for wrist four direction movements monitoring.