Dual-Mode Fiber Strain Sensor Based on Mechanochromic Photonic Crystal and Transparent Conductive Elastomer for Human Motion Detection

Abstract

As an important component of wearable and stretchable strain sensors, dual-mode strain sensors can respond to deformation via optical/electrical dual-signal changes, which have important applications in human motion monitoring. However, realizing a fiber-shaped dual-mode strain sensor that can work stably in real life remains a challenge. Here, we design an interactive dual-mode fiber strain sensor with both mechanochromic and mechanoelectrical functions that can be applied to a variety of different environments. The dual-mode fiber is produced by coating a transparent elastic conductive layer onto photonic fiber composed of silica particles and elastic rubber. The sensor has visualized dynamic color change, a large strain range (0−80%), and a high sensitivity (1.90). Compared to other dual-mode strain sensors based on the photonic elastomer, our sensor exhibits a significant advantage in strain range. Most importantly, it can achieve reversible and stable optical/electrical dual-signal outputs in response to strain under various environmental conditions. As a wearable portable device, the dual-mode fiber strain sensor can be used for real-time monitoring of human motion, realizing the direct interaction between users and devices, and is expected to be used in fields such as smart wearable, human−machine interactions, and health monitoring.

Advance on fiber optic‐based biosensors for precision medicine: From diagnosis to therapy

“…80,81 The fiber optic sensor is a powerful tool for sensing humidity, pressure, and strain, showing promising potential for wearable breath, 35 temperature, 36 and sport monitoring. 37 Bao et al fabricated an eccentric fiber Bragg grating inscribed single mode fiber optic, 35 as shown in Figure 4A. The cladding mode was highly sensitive to the change in refractive index induced by humidity, and the core mode maintained stable spectral feature.…”

“…[32][33][34] The sensing area of the fiber optic-based biosensor can laminate onto the epidermis or be implanted into the body. The research interest of wearable and implanted biosensors has been extended from physical exercise activities to specialized healthcare, including breath, 35 temperature, 36 sport monitoring, 37 pH, 38 dissolved oxygen, 39 and neurochemical. 40 The critical information about our healthcare brings the important evidence for the clinical diagnosis and provides significant guidance for the therapy.…”

Intelligent health and sport: An interplay between flexible sensors and basketball

“…In recent years, flexible sensors have been widely researched and used in electronic skin, medical care, sports equipment, textiles, aerospace, environmental monitoring, and other fields. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 Flexible sensors can withstand mechanical deformation such as bending, rolling, folding, stretching, twisting, and conforming without device failure or significant alteration in sensing performance. 10 Their advantages on flexibility, stretchability, and shape adaptability make them well suited for measurements on dynamic and/or shape-changing objects and large-area non-flat surfaces like the human body, with which rigid sensors typically struggle.…”

Biomimetic Photonic Elastomer Exhibiting Stress/Moisture Reconfigurable Wrinkle-Lattice for Reversible Deformation Information Storage

“…Chameleon’s skin contains a three-dimensional organized structure of guanine nanocrystals . This unique structure empowers chameleons to dynamically adjust the spacing of the array, enabling them to alter their skin color effortlessly and effectively blend into their surroundings at an optical level. , The self-regulation mechanism serves as profound inspiration for the advancements of mechanochromic materials. − Photonic elastomers represent a promising material category, where an elastomeric framework is integrated into a nanoscale periodic structure which exhibits the ability to undergo highly saturated, multicolored transformations within the visible light range with the sole input of mechanical energy-induced deformation. − Its potential applications span various fields, including mechanical sensing, displays, anticounterfeiting, and photonic skins. − For instance, the incorporation of ordered or short-range ordered spherical nanoparticles array into a carefully designed elastic polymer network renders the photonic thin film capable of exhibiting tunable structural color characteristics during deformation events. , Presently, studies on photonic elastomers predominantly focus on the synchronous feedback of optical signals with deformation behaviors. , When deformation occurs, the structural color blue-shifts due to elastic lattice compression. Following the cessation of deformation, rapid color restoration takes place due to the superior performance of the elastic medium filling the voids .…”