Hydrogels are classical soft and wet materials that have been extensively studied over the past several decades.Recently,with the development of supramolecular science,nanotechnology and precisely synthetic chemistry,various novel hydrogels have been designed and fabricated,which show emerging applications in tissue engineering,drug delivery,anti-fouling coatings,flexible electronics and soft robotics.Through tailoring their two-dimensional surface structures and three- Hydrogels are classical soft and wet materials that have been extensively studied over the past several decades. Recently, with the development of supramolecular science, nanotechnology and pre-filled chemistry chemistry, various novel hydrogels have been designed and fabricated, which show emerging applications in tissue engineering, drug delivery, anti-fouling coatings, flexible electronics and soft robots. Through tailoring their two-dimensional surface structures and three-