Flexible mechano-optical sensors from mechanoluminescence to mechanoplasmonics: designs, applications, and prospects

Abstract

Flexible mechano-optical sensors (FMOS) achieve quantitative sensing of mechanical stimuli by monitoring changes in optical response, and due to the incorporation of a polymeric matrix/substrate, they exhibit high flexibility, elasticity, and biocompatibility. This wireless and visualized sensing capability offers potential for both in situ and in vivo applications. In this review, we delve into the mechanisms and developments of two types of FMOS: “active” mechanoluminescence (ML) and “passive” mechanoplasmonics (MP). The focus is on how ML particles and polymers can be combined in various configurations (such as bulk, laminar, and woven blending systems) to yield robust, multifunctional, and hybrid optical/electrical properties, exploring their potentials in engineering, information, and wearable/implantable applications. Additionally, the tunability of ML intensity and emission color under mechanical and various environmental stimuli is summarized, leading to a discussion on the versatile MP nanostructures. With their sophisticated artificial design, MP demonstrates promise for both small-scale sensing and high-level control over spectral wavelength and intensity. Lastly, based on current research on ML and MP, challenges and prospects for combining these two technologies to advance the field of FMOS are proposed.