Bio-inspired multi-point positioning fiber array sensor with epidermis-dermis interlocking structure

Abstract

This study proposes a passive bio-inspired multi-point positioning fiber array sensor (BMPFAS) based on an epidermal-dermal interlocking structure, which realizes optical spatial localization of six pressure contact points through a passive photonic tactile sensing array. The sensor adopts a ternary modular design comprising mechanoluminescence, waveguide transmission, and dual-channel detection. In the biomimetic transduction layer, a microstructured photonic emission array is constructed via embedded heterogeneous integration of quartz optical fibers and an inorganic luminescent matrix. Photons generated by mechanical-stimulus-induced mechanoluminescent (ML) materials are coupled into the fiber end-faces and transmitted through a multiplexed optical fiber network composed of cascaded 1 × 2 optical couplers, reaching a dual photomultiplier tube (PMT) terminal for synchronous intensity quantification and signal decoupling. A stress-field modulation mechanism is introduced via a gradient modulus ratio ($E_{\mathrm{upper}}:E_{\mathrm{lower}}\approx 1.8:1$), and combined with a self-healing ML layer, enabling a 154 % enhancement in luminescence intensity under dynamic surface deformation. This technological breakthrough provides a passive photonic solution for tactile perception in intelligent robotics, wearable health monitoring, and human–machine interface development.