Optical fiber membrane-based Fabry–Perot tactile force sensing platform powered by LED ambient lighting

Abstract

This study introduces an optical fiber tactile force sensing platform powered by ambient LED lighting. Based on the interaction between a multimode optical fiber and a micro-polymer membrane, it is possible to excite an Extrinsic Fabry-Perot Interferometer (EFPI); this EFPI is pumped by collected incident light from the ambient LED lighting environment; here, a Fresnel lens and multimode fiber collect this light. The collector system maintains suitable light intensity even during 360° rotation. When transversal loads between 0 to 1 N are applied over the membrane, the tactile force sensor shows a wavelength shift towards shorter wavelengths; consequently, a 6.5 nm/N sensitivity and resolution of 0.15 N are obtained. Moreover, the phase analysis of the Fourier spectrum addresses intensity variations during rotation, revealing a sensitivity of 3 rad/N. The sensor offers stability, minimal hysteresis, minimal temperature modulation, and suitable time response across four sensing areas. Moreover, the statistical analysis and tactile force sensor performance ensure reliable tactile measurement with a null probability of overlap upon force application. It is crucial to note that this tactile force sensor provides a genuinely low-cost implementation due to the utilization of ambient LED lighting as the light source. This aspect represents an exciting advancement in fiber sensing technology.