Abstract: Systems and methods for three-dimensionally printing different configurations of a printed fiber using a single nozzle are provided. The provided systems and methods harness deformation, instability, and fracture of viscoelastic materials to adjust dimensionless parameters related to a speed of extrusion and a height of a nozzle to create the different configurations. A controller of the system can operate to create these different configurations using the single nozzle without having to change out hardware during the process. Instead, the dimensionless parameters can be adjusted while the printing is occurring to achieve the different configurations. The disclosure provides various systems for carrying out the printing, and methods of using the same.

Abstract: Dry adhesive materials, particularly in the form of a film or tape, for adhering one or more wet surfaces comprising: (i) one or more hydrophilic polymers; (ii) one or more amine coupling groups, and (iii) one or more cross linkers. The dry adhesive material, when placed in contact with the one or more wet surfaces, absorbs liquid from the one or more wet surfaces, swells to form temporary crosslinking with the wet surface, and forms covalent crosslinking with the one or more wet surfaces.

Abstract: Pure conducting hydrogel precursors and hydrogels formed of pure conducting polymer materials having a combination of high electrical conductivity, high stretchability, low Young's modulus, superior mechanical, electrical and electrochemical stability, and tunable swelling behaviors in wet physiological environments. The hydrogel precursors and hydrogels are fabricated by adding a polar organic solvent to an aqueous solution of the pure conducting polymer material, followed by controlled dry-annealing to form a hydrogel precursor which can be subsequently rehydrated to form a pure conducting polymer hydrogel which comprises at least 99% of the pure conducting polymer.

Abstract: A responsive material having an elastomeric matrix in which ferromagnetic particles are dispersed so as to have a predetermined magnetization pattern which, when exposed to an external magnetic field, changes the shape of the responsive material from an initial shape to a predetermined transformed shape dictated by the magnetization pattern. An initial shape of the responsive material is formed by direct ink printing while applying magnetic fields to a dispensing nozzle to align the particles and gives rise to the desired magnetization pattern.

Abstract: Hydrogel-substrate laminate structures and tough biocompatible hydrogel coatings for various equipment such as medical devices and underwater equipment, in which robust interfaces are formed between the hydrogel coatings and the substrate/equipment surface(s). The hydrogel coatings provide a highly-hydrated, ultra-low friction structure that does not rupture or delaminate under stress. The hydrogel coatings may further incorporate a variety of therapeutic agents and/or sensing mechanisms to provide for environmental sensing and therapeutic agent release.

Abstract: Hydrogel-elastomer hybrids with interfacial bonding tougher than epidermis-dermis interfaces and functional micro-channels and micro-patterns can be created by pre-shaping both elastomers and hydrogels before bonding to conserve their micro-structures, modifying cured elastomer surfaces with benzophenone for chemical bonding with hydrogels, and harnessing dissipative properties of tough hydrogels to achieve robust interfaces.

Abstract: A method for making a tough and compliant hydrogel. A precursor hydrogel is made of a first polymer selected to maintain high elasticity and a second polymer selected to dissipate mechanical energy. The precursor hydrogel is stretched to a multiple of its original length to form a pre-stretched hydrogel. The pre-stretched hydrogel is allowed to relax and is soaked in a biocompatible solvent to reach equilibrium swelling of the pre-stretched hydrogel whereby shear modulus of the hydrogel is reduced.

Abstract: Method for making a tough and compliant hydrogel. A precursor hydrogel is made of a first polymer selected to maintain high elasticity and a second polymer selected to dissipate mechanical energy. The precursor hydrogel is stretched to a multiple of its original length to form a pre-stretched hydrogel. The pre-stretched hydrogel is allowed to relax and is soaked in a biocompatible solvent to reach equilibrium swelling of the pre-stretched hydrogel whereby shear modulus of the hydrogel is reduced.

Abstract: Chemically anchoring long-chain polymer networks of tough hydrogels on solid surfaces can represent a general strategy to design tough and functional bonding between hydrogels and solid materials, achieving interfacial toughness over 1000 Jm?2.

Abstract: A tough biocompatible hydrogel having one or more drug delivery components, deformable conductors, and/or rigid electronic components incorporated therein in such a way that robust interfaces are formed between the hydrogel and the various components. The resulting hydrogel device provides a highly deformable hydrogel composite in which the reliability and functionality of the incorporated components are maintained even under states of large deformation, and from which one or more drugs can be delivered in a controlled and sustained manner regardless of the state of deformation.

Abstract: Method for making a tough and compliant hydrogel. A precursor hydrogel is made of a first polymer selected to maintain high elasticity and a second polymer selected to dissipate mechanical energy. The precursor hydrogel is stretched to a multiple of its original length to form a pre-stretched hydrogel. The pre-stretched hydrogel is allowed to relax and is soaked in a biocompatible solvent to reach equilibrium swelling of the pre-stretched hydrogel whereby shear modulus of the hydrogel is reduced.