Adhesive Tough Magnetic Hydrogels with High Fe3O4 Content

] as the inclusions. This magnetic hydrogel not only offers a relatively high modulus and toughness compared to the pure hydrogel but also responds to the magnetic field rapidly because of high magnetic particle content (up to 60%, with respect to the total weight of the polymers and water). The hydrogel can be bonded to hydroxyl-rich hard and soft surfaces. Magnetic hydrogel with polydimethylsiloxane (PDMS) coating exhibits excellent underwater performance. The bonding between magnetic hydrogel and PDMS is very stable even under cyclic loading. An artificial muscle and its magnetomechanical coupling performance are demonstrated using this hydrogel. The adhesive tough magnetic hydrogel will open up extensive applications in many fields, such as controlled drug delivery systems, coating of soft devices, and microfluidics. The strategy is applicable to other functional soft materials.