Abstract
Flexible sensors and antennas are increasingly deployed in wearable health monitoring, environmental sensing, and RFID technology, yet their reliability under environmental exposure remains insufficiently addressed. This review synthesizes the literature on the environmental degradation of flexible sensors and antennas, with particulate-induced degradation as the primary stressor and humidity and temperature treated as cofactors; additional mechanisms such as flexural fatigue and UV-induced photodegradation are briefly addressed but beyond the scope. Across the literature, dust-induced degradation rarely acts independently: moisture ingress within the substrate repeatedly appears as a shared vulnerability that could: (a) shift dielectric properties, (b) enable moisture transport about the conductor surface, and (c) promote electrolyte formation through ionic particulate deposition, accelerating electrochemical degradation. Temperature further amplifies these mechanisms by accelerating moisture diffusion and reaction kinetics and by promoting the generation of microcracks through CTE mismatch and cyclic fatigue, which create sites for moisture ingress and particulate deposition. We conclude with a layered mitigation architecture spanning encapsulation, substrate selection, conductor and material engineering, and geometric design. Building on this architecture, we propose a provisional (prototype-like) three-axis design framework that classifies deployment environments by aqueous ionic conductivity of particulate deposits, sustained relative humidity, and operating temperature with cycling amplitude, mapping each of the 27 combinations to a candidate mitigation prescription. We identify key experimental gaps; most notably, the scarcity of dust deposition studies on flexible sensors and antennas and the absence of comparative substrate testing across the three stressors, simultaneously. Addressing these knowledge gaps could enable the development of mechanically robust, environmentally resilient flexible systems for wearable technologies, while also facilitating the exploitation of dust-induced surface degradation as a functional transduction mechanism for sensing applications. A Limitation Section is included to highlight the fact that sufficient particulate-deposition studies on flexible sensors and antennas remain elusive, which provides opportunities for future research. While some mechanistic effects and material characterization are extrapolated from rigid PCB and MEMS studies, this does not constitute direct experimental support for their flexible counterparts.