Water-stable metal-organic frameworks-based materials for strain sensors

Metal-organic frameworks (MOFs) are porous materials characterized by elevated surface areas and adjustable structures, rendering them appropriate for applications such as catalysis, water purification, and sensor technology. MOFs have potential in flexible pressure and strain sensors due to their adjustable host-guest interactions and structural flexibility; yet, issues persist in aligning MOF characteristics with sensor mechanisms. Key performance parameters—sensitivity, linearity, flexibility, hysteresis, durability, and operational range—are improved using sophisticated material techniques, including piezoelectric or piezoresistive effects, microstructural optimization, and the application of resilient composites such as polydimethylsiloxane. Piezoresistive, capacitive, and piezoelectric sensing techniques are utilized, each providing distinct benefits in terms of response and sensitivity. Progress in nanocomposites, three-dimensional structuring, and porous designs has enhanced sensor efficacy, especially in wearable electronics, healthcare, and robotics. MOFs combined with conductive nanocomposites produce flexible piezoresistive sensors characterized by high sensitivity, rapid reaction times, and efficient physiological signal monitoring. Methods for the synthesis of MOFs, including hydro/solvothermal synthesis, assembly, and vapor deposition, are essential for sensor development. Recyclable ionogel-based and carbonized MOF sensors provide sustainable solutions for biomedical devices, soft robotics, and industrial applications, highlighting the adaptability and potential of MOFs in multifunctional, high-performance sensors.