Stretchable and body-conformable physical sensors for emerging wearable technology

Wearable physical sensors represent attractive devices for health monitoring and human-machine interfaces. Unlike traditional devices that prioritize increased sensitivity and selectivity, stretchability is crucial for wearable sensors to effectively adhere to the dynamic and curved contours of the human body. In addition to being stretchable, the conformal integration allows for durable skin-device interfaces, enabling long-term wearable detection. To track the latest progress, this perspective focuses on the rapidly advancing field of skin-attached physical sensors, analyzing their design approaches, critical applications, and desirable characteristics. The discussion begins with two primary strategies for creating stretchable electronic devices through structural designs and material innovations. We further discuss the significance of a conformal, seamless skin-device interface for wearable detection. We further elaborate on several critical physical sensors and their system integration. Finally, this article addresses current challenges and outlines future directions to translate knowledge in this evolving field into cutting-edge wearable technologies. Intimate interfaces can significantly increase the contact areas on textured skin surfaces, thereby enhancing sensing signals. Consequently, it is essential to impart stretchability and body conformability to physical sensors for wearable detection.