Robotic grasping in unstructured environments demands closed-loop feedback that goes beyond conventional fixed open-loop force control. Vision sensors suffer from occlusion at the instant of contact, whereas wrist-mounted force/ torque sensors cannot resolve local shear stress distributions or incipient slip at multi-contact interfaces. Tactile sensors bridge this gap by mapping high-dimensional contact physics directly and in real time. This paper surveys grasp intelligence technology within a Perception–State Estimation–Action framework. Specifically, it reviews optical and arraytype tactile sensors; slip detection algorithms, ranging from physics-based local deformation analysis to deep spatiotemporal networks; and active closed-loop force regulation, including diffusion-policy-based reactive control. Applications in precision semiconductor and electronics assembly are then discussed. Finally, outstanding challenges in mechanical durability, ultra-low-latency data processing, intelligent tactile skin, and multi-modal Vision-Language-Action integration are identified as priorities for future research.