Wearable sensors are compact devices that continuously monitor signals from the human body and environment, enabling real time health and activity tracking. Recent research focuses on making these sensors flexible, stretchable and comfortable so they can be integrated into clothing, patches, or directly on skin.

A major theme is the development of electronic skin, or e skin, which mimics the mechanical properties of human skin while measuring pressure, strain, temperature, and bioelectrical signals. Soft polymers, nanomaterials, and ultrathin conductive films are engineered into networks that maintain performance under bending and stretching. Some designs use microstructured surfaces or serpentine interconnects to preserve conductivity during motion.

Another important direction is multimodal sensing. Devices combine motion tracking, physiological measurements such as heart rate, respiration, and sweat composition, and environmental parameters like temperature or gas concentrations. Integration of different sensors on a single flexible platform helps capture a more complete picture of health and behavior.

Power and data handling are central challenges. Researchers explore low power electronics, energy harvesting from motion or body heat, and wireless data transmission via Bluetooth or near field communication. Efforts also target on board signal processing to reduce data volume and enable early detection of anomalies.

Applications include continuous monitoring of cardiovascular and respiratory health, rehabilitation and athletic performance analysis, early detection of neurological disorders, and tracking exposure to toxic substances. Emerging work combines wearable sensors with machine learning to classify activities or predict health events. Overall, the field is moving toward unobtrusive, durable systems that seamlessly integrate into daily life while providing clinically meaningful data.