WS₂ among the TMD family was found to be exfoliated with maximum effiiency by the assistance of lowcost marine SA; SA among a series of polysaccharides could exfoliate WS₂ with maximum effiiency. This perfect couple originates from strong interactions of H-bonding and coordination between SA and WS₂, where an unprecedented concentration up to 1.39 mg mL⁻¹ of thin-layer WS₂ was achieved. The presence of strong interactions also enabled tunable filerloading levels in their composites without showing filer aggregation. Exfoliated WS₂ effiiently conveyed their exceptional properties to the macroscopic scale, e.g., strong mechanical properties (i.e., tensile strength of 422.5 MPa and toughness of 25.76 MJ m⁻³) superior to natural biocomposites (e.g., nacre, bone and dentin), and NIR-active photothermal ability (e.g., up to 300 °C with seconds of low-dose radiation). The waterabsorption and cation-binding capacities of SA further endow the composites with super multiple-stimuli driven actuating applications, e.g., a NIR-driven motor, walking robot, and gripper. The discovery of exfoliation ability in this low-cost marine polysaccharide may pave a new way to expand applications of TMDs in biotechnology, material science, and nanotechnology. These bioinspired smart properties also imply huge potential in development of soft robotics and smart devices.