Silly Putty-like material with tunable mechanical properties, unique rheological behavior and recyclable molding ability has emerged as a promising material for wide-spread use in bionic robots, energy storage and intelligent monitoring devices. To overcome the common heterogeneous aggregation or phase separation problems relating to traditional Silly Putty-like materials, a simple method is proposed here to produce a hydrogel with good self-healing, conductivity and photothermal conversion properties based on dynamic metal–ligand interactions and hydrogen bonds by simply mixing phytate polyvinyl alcohol, pyrrole and Fe³⁺. The introduction of coordinate bonds endowed the hybrid hydrogel with special rheological behaviors, such as solid–liquid like and shear-thinning properties, which would enable the use of injectable techniques and remolding processing for the Silly Putty-like hydrogel. Moreover, due to a wide range of light absorption by the black conductive polymer, the hydrogel also had a good photothermal conversion capacity, so could be useful for reliable photothermal imaging, portable photothermal therapy or sensitive temperature sensing applications. Combined with previous properties, this hydrogel may play a potential role in electronics manufacturing, medical testing and therapy.

Photothermal conversion in the near-infrared (NIR) wavelengths, wherein light energy is converted into heat energy, has attracted great interest and developed rapidly in recent years for its wide applications in health care, flexible electronics, energy and environmental fields. However, the photothermal temperature, as one of the most important parameters in the NIR photothermal conversion, still has not been effectively studied. Herein, we successfully achieved ultrahigh photothermal temperatures in a graphene/conducting polymer system. The surface temperature of the prepared free-standing reduced graphene oxide/polypyrrole (rGO/PPy) foam can be as high as 380 °C with 808 nm NIR irradiation at 2.6 W cm⁻², and the surface temperature of the rGO/PPy film on the polydimethylsiloxane (PDMS) substrate can be as high as 310 °C under the same conditions. The photothermal energy has been used for burning, thermopolymerization, alloying reactions and thermal decomposition reactions, providing new directions for photothermal conversion beyond photothermal therapy and energy utilization.

Soft robots, with their compliant bodies, minimal environmental disturbance, and ability to withstand ambient pressures, offer promising solutions for deep-sea exploration. However, a common challenge of stiffening in soft materials impairs their effective actuation in harsh conditions. In this work, we integrated a liquid dielectric plasticizer within an electrohydraulic soft robot, serving dual critical functions as a softening agent to maintain the softness of the polymer shell and an electrohydraulic fluid for efficient actuation. In addition, by using the surrounding seawater as alternating electrodes, we prevented charge retention in dielectric layers, enabling sustained actuation performance. Field tests at depths of ~1360, 3176, and ~4071 meters confirmed the robot’s ability to sense the environment, navigate complex trajectories, and withstand unsteady disturbances. Our work offers a generalized and straightforward framework for developing soft materials tailored for deep-sea applications, paving the way for soft robots to execute real-world missions.

Supramolecular polymers show unique and excellent properties due to the reversible and designable nature of the non-covalent interactions. Herein, ureido-pyrimidinone (UPy)-based supramolecular polymers were employed to fabricate the thermo-responsive composite materials with multi-walled carbon nanotubes (MWCNTs) by planting the MWCNTs onto the supramolecular polymer matrices via a simple surface spraying procedure. The MWCNTs coating on the surface of the supramolecular polymer matrices gave the composite film superhydrophobic and conductive properties, and it had a non-contact healable ability underwater under 808 nm near-infrared light (NIR) irradiation. Moreover, the UPy-based supramolecular polymers acted as thermo-responsive matrices to guarantee the self-healing properties at a relatively low temperature, such as body temperature (33 °C–34 °C). The supramolecular polymer/MWCNTs composite materials exhibited excellent strain sensitivities and could be used to prepare human motion-monitoring devices. This line of research may find a promising practical application in healable wearable devices used in underwater environments.