Many biological organisms can tune their mechanical properties to adapt to environments in multistable modes, but the current synthetic materials, with bistable states, have a limited ability to alter mechanical stiffness. Here, we constructed programmable organohydrogels with multistable mechanical states by an on-demand modular assembly of noneutectic phase transition components inside microrganogel inclusions. The resultant multiphase organohydrogel exhibits precisely controllable thermo-induced stepwise switching (i.e., triple, quadruple, and quintuple switching) mechanics and a self-healing property. The organohydrogel was introduced into the design of soft-matter machines, yielding a soft gripper with adaptive grasping through stiffness matching with various objects under pneumatic-thermal hybrid actuation. Meanwhile, a programmable adhesion of octopus-inspired robotic tentacles on a wide range of surface morphologies was realized. These results demonstrated the applicability of these organohydrogels in lifelike soft robotics in unconstructed and human body environments.
Energy-dissipation elastomers relying on their viscoelastic behavior of chain segments in the glass transition region can effectively suppress vibrations and noises in various fields, yet the operating frequency of those elastomers is difficult to control precisely and its range is narrow. Here, we report a synergistic strategy for constructing polymer-fluid-gels that provide controllable ultrahigh energy dissipation over a broad frequency range, which is difficult by traditional means. This is realized by precisely tailoring the relaxation of confined polymer fluids in the elastic networks. The symbiosis of this combination involves: elastic networks forming an elastic matrix that displays reversible deformation and polymer fluids reptating back and forth to dissipate mechanical energy. Using prototypical poly (n-butyl acrylate) elastomers, we demonstrate that the polymer-fluid-gels exhibit a controllable ultrahigh energy-dissipation property (loss factor larger than 0.5) with a broad frequency range (10−2 ~ 108 Hz). Energy absorption of the polymer-fluid-gels is over 200 times higher than that of commercial damping materials under the same dynamic stress. Moreover, their modulus is quasi-stable in the operating frequency range.
Adaptive materials with reconfigurable surface topography in response to external environments have attracted considerable attention in various fields. Here, adaptive superamphiphilic organohydrogels with reconfigurable surface topography are reported, featuring a high degree of freedom. The organohydrogels can simultaneously adapt to different surrounding mediums and reversibly switch between hydrogel-and organogeldominated surface reconfigurations to realize adaptive superhydrophilic and superoleophilic transitions. Meanwhile, these adaptive organohydrogels possess a heteronetwork complementary effect to elicit surface self-healing capacity. Importantly, owing to these organohydrogels' reversible wettability transition, excellent surface morphing performance and bioinspired strategy, various geometrically complex biomimetic topographies can be programmed, offering unique unidirectional transport for opposite-featured liquids in multimedia environments. Smart organohydrogel-based microfluidic devices are also developed for on-demand remote programming of liquid transport. Therefore, the organohydrogels suggest a reconfigurable surface topography design strategy, and would act as adaptive programmable materials for smart surface applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.