Ionic flexible force sensors and their potential applications

Flexible sensors are core components of intelligent wearable technology, and they are rapidly developing. Among these, flexible force sensors use flexible sensing materials to convert stress and strain into electrical signals. However, when the ionic flexible force sensor is subjected to external mechanical force, it will cause uneven distribution in the internal ions and generate electrical signals. This can be used to resolve issues with sensors to distinguish the stress or strain direction, by applying positive and negative electric potential without an external power supply. In addition, this integration process is simple and convenient. This review article describes the working mechanism of ionic flexible force sensors and describes the materials and properties used in these sensors, including electrolyte layer materials and electrode materials. We then list the latest applications in the fields of health care, motion detection, intelligent 3D robots and so on. Finally, we highlight the current limitations and future development of ionic flexible force sensors, to simultaneously develop new materials and technology with improved sensitivity for mass production.