With the rapid advancements in wearable sensor technology, healthcare is witnessing a transformative shift towards personalized and continuous monitoring. Wearable sensors designed for tracking human strain offer promising applications in rehabilitation, athletic performance, occupational health, and early disease detection. Recent advancements in the field have centered on the design optimization and miniaturization of wearable biosensors. Wireless communication technologies have facilitated the simultaneous, non-invasive detection of multiple analytes with high sensitivity and selectivity through wearable biosensors, significantly enhancing diagnostic accuracy. This review meticulously chronicles noteworthy advancements in wearable sensors tailored for healthcare and biomedical applications, spanning the current market landscape, challenges faced, and prospective trends, including multifunctional smart wearable sensors and integrated decision-support systems. The domain of flexible electronics has witnessed substantial progress over the past decade, particularly in flexible strain sensors, which are crucial for contemporary wearable and implantable devices. These innovations have broadened the scope of applications in human health monitoring and diagnostics. Continuous advancements in novel materials and device architectural methodologies aim to expand the utility of these sensors while meeting the increasingly stringent demands for enhanced sensing performance. This review explores the diverse array of wearable sensors-from piezoelectric, piezoresistive, and capacitive sensors to advanced optical and bioimpedance sensors-each distinguished by unique material properties and functionalities. We analyzed these technologies' sensitivity, accuracy, and response time, which were crucial for reliably capturing strain metrics in dynamic, real-world conditions. Quantitative performance comparisons across various sensor types highlighted their relative effectiveness, strengths, and limitations regarding detection precision, durability, and user comfort. Additionally, we discussed the current challenges in wearable sensor design, including energy efficiency, data transmission, and integration with machine learning models for enhanced data interpretation. Ultimately, this review emphasized the revolutionary potential of wearable strain sensors in advancing preventative healthcare and enabling proactive health management, ushering in an era where real-time health insights could lead to more timely interventions and improved health outcomes.
