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Owing to wearing and unpredictable damage, the working lifetime of triboelectric nanogenerators (TENGs) is largely limited. In this work, we prepared a single-electrode multifunctional TENG (MF-TENG) that exhibits fast self-healing, human health monitoring capability, and photothermal properties. The device consists of a thin self-healing poly­(vinyl alcohol)-based hydrogel sandwiched between two self-healing silicone elastomer films. The MF-TENG exhibits a short-circuit current, short-circuit transfer charge, and open-circuit voltage of 7.98 μA, 78.34 nC, and 38.57 V, respectively. Furthermore, owing to the repairable networks of the dynamic imine bonds in the charged layer and the borate ester bonds in the electrodes, the prepared device could recover its original state after mechanical damage within 10 min at room temperature. The MF-TENG can be attached to different human joints for self-powered monitoring of personal health information. Additionally, the MF-TENG under near-infrared laser irradiation can provide a photothermal therapy for assisting the recovery of human joints motion. It is envisaged that the proposed MF-TENG can be applied to the fields of wearable electronics and health-monitoring devices.

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A dielectric elastomer actuator with excellent electromechanical performance was fabricated by incorporating modified barium titanate into slide-ring materials with necklace-like molecular structure.

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Aligned multi-walled carbon nanotubes (MWCNTs)/polyvinyl alcohol composite films were prepared by using an easy and controllable electrospinning-in situ film-forming (EF) technique. A high dielectric constant (k), a low dielectric loss, a consistently high breakdown strength, and a high energy density were obtained by using this technique. The dramatically improved dielectric properties are ascribed to the good dispersion and alignment of MWCNTs in the matrix, facilitating the formation of a large number of separated nano-capacitors (high k and low direct current (DC) conductance). For comparison purposes, the same composite films were prepared by solution casting (SC). At the same MWCNT content, the SC method yielded a higher k, but a significantly higher dielectric loss and much lower breakdown strength and energy density because of the random dispersion of MWCNTs in the matrix and the formation of a MWCNT network, which result in a large increase in DC conductance. The formation mechanism of the different microstructures and the relationships between the microstructures and dielectric properties are clarified. Our results indicate that high-performance MWCNTs/polymer dielectric composites can be obtained by controlling the microstructure of the composites by using the EF technique, which widens the applications of dielectric materials.