Integrated sensing and colour expression of spatial status using a fibre optic sensor pair

Fibre optic sensors are widely used to monitor structural deformation. In conventional systems, the optical sensing signals are first converted into electrical signals for subsequent processing by integrated circuits, and the results are then displayed on external devices. As a result, traditional fibre optic sensors generally only have sensing capabilities and lack the ability to directly convey information about the detected deformation. This paper presents a fibre optic sensing strategy that integrates both sensing and expression, using a pair of dissipative optical fibre sensors embedded in a deformable, translucent soft material. Through the structural design of optical fibres, the optical fibres generate directionally related light leakage when bending the fibres. The spatial information associated with the bending is encoded in colour by the sensor pair and shown on the soft material, thereby expressing its spatial information to the outside world. This allows real-time, visual expression of spatial status-related information. This strategy extends the functional boundaries of fibre optic sensors, from passive sensing to sensing and colour expression. This integrated sensing-expression approach could offer rapid-response interaction for some applications in systems such as soft robots and wearable devices. • A fibre optic sensor pair embedded in soft material enables simultaneous deformation sensing and direct colour expression. • Directionally controllable light leakage encodes bending-related spatial information into visible colours without electronic processing. • The integrated sensing–expression strategy provides real-time visualisation for soft robots, wearable devices, and other interactive systems.