10. Printed Flexible Sensors and Sensing Systems

Printed flexible sensors have the potential to be seamlessly applied to soft and irregularly shaped surfaces such as human skin or textile fabrics. Owing to its varied range of applications in the field of flexible and wearable electronics, soft robotics, human–machine interaction, and biomedical devices, it is required of these sensors to be flexible and stretchable conforming to the arbitrary surfaces of their soft or stiff counterparts. The challenges in maintaining the fundamental features of these sensors, such as flexibility, sensitivity, repeatability, linearity, and durability, are tackled by the progress in the fabrication techniques and customization of the material properties. As a result, materials and structures for innovative flexible sensors, as well as their integration into systems, continue to be in the spotlight of research. This chapter outlines the current state of flexible sensor technologies and the impact of material developments on this field. Special attention is given to stress, strain, temperature, chemical, electropotential, and magnetic sensors, as well as their respective applications.