High-resolution flexible tactile sensors

Flexible tactile sensors serve as the essential sensory interfaces for compliant physical interaction in advanced intelligent systems, such as embodied intelligence robotics and smart wearable devices. To meet the increasing demand for rich and precise tactile information, achieving high-resolution perception has become a vital performance metric for these flexible tactile sensing systems. This review presents a systematic overview of flexible tactile sensors from the perspective of high-resolution realization mechanisms, mainly encompassing two paradigms: array-based spatial information sampling via discrete taxel layouts, and array-free spatial information inference over continuous tactile sensing medium. First, dense taxel layouts are introduced as conventional array-based strategies for high-resolution realization. Then, the emerging sparse layout strategies enabled by artificial intelligence algorithms are described, achieving super-resolution sensing beyond physical layout density. Subsequently, we summarize the array-free strategies for high-resolution tactile sensing over continuous sensing medium, focusing on physics-based inference and learning-based prediction. In addition, we show typical examples of their applications in enhanced interaction scenarios. Finally, future trends toward scalable, generalizable, multimodal, and highly integrated flexible tactile sensing systems are discussed, with scientific challenges and potential development pathways outlined.