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Dielectric elastomers, used as driver modules, require high power density to enable fast movement and efficient work of soft robots. Polyacrylate elastomers usually suffer from low power density under low electric fields due to limited response frequency. Here, we propose a bimodal network polyacrylate dielectric elastomer which breaks the intrinsic coupling relationship between dielectric and mechanical properties, featuring relatively high dielectric constant, low Young's modulus, and wide driving frequency bandwidth (~200 Hz) like silicones. Therefore, an ultrahigh power density (154 W kg−1@20 MV m−1, 200 Hz) is realized at low electric field and high resonance frequency, 75 times greater than at 10 Hz. Further, a rotary motor is developed, reaching an impressive speed of 1245 rpm at 19.6 MV m−1 and 125 Hz, surpassing previous acrylate-based motors and entering the high-speed domain of silicone-based motors. These findings offer a versatile strategy to fabricate high-power-density dielectric elastomers for low-electric-field soft actuators. The authors make a bimodal network polyacrylate dielectric elastomer featuring high driving frequency like silicones and thereby a high power density of 154 W kg−1@20 MV m−1, 200 Hz. Their rotary motor realizes a maximum rotating speed of 1245 rpm@ 19.6 MV m−1. [ABSTRACT FROM AUTHOR]

Dielectric elastomer actuators (DEAs) face an acknowledged challenge: On the one hand, the majority of elastomers only achieve small electroactive deformation (<20%) in the absence of prestretch; on the other hand, rare elastomers capable of showing large electroactive deformation require relatively complicated processing and chemistry. This work addresses this challenge by fabricating an elastomer with a network of large side groups, which achieves a very large electroactive deformation (218%) without pre‐stretch. This elastomer can be rapidly and massively fabricated within a few min, by polymerizing a commercial monomer with a large alkyl side group. The large side groups in the polymer network repel each other and extend the load‐bearing strands, which results in a pronounced strain‐hardening behavior. This behavior helps the elastomer to get rid of electromechanical instability during actuation and hence to exhibit a large electro‐active deformation, a high energy density (>> human muscle), and a large output force (≈500 times self‐weight). the elastomer capable of manufacturing a soft electroactive gripper is demonstrated with large deformation, large force, and rapid response, which enables grasping fragile objects of various complex shapes in an agile away. [ABSTRACT FROM AUTHOR]

Polymer‐based dielectrics with fast electrostatic energy storage and release, are crucial for advanced electronics and power systems. However, the deterioration of insulation performance and charge–discharge efficiency of polymer dielectrics at elevated temperatures and high electric fields hinder the applications of capacitors in harsh environments. Herein, a facile and scalable approach is reported to fabricating flexible high‐temperature polymer dielectrics for high‐efficiency energy storage by ultraviolet irradiation. The resultant dielectric films exhibit an augment of 493% in energy density and exceeding 800% in discharge efficiency at 200 °C (3.2 J cm−3 and over 90% discharge efficiency at 480 M V−1m for irradiated polyetherimide (PEI), 0.54 J cm−3, and below 10% discharge efficiency at 400 MV m−1 for pristine PEI) and excellent cycle performance. The injected space charge is found to be the dominant contributor to energy loss during the charge–discharge process. Free radicals introduced by ultraviolet irradiation can act as deep traps to capture injected charge and suppress space charge migration. This work clarifies the contribution of space charge to energy loss and demonstrates the effectiveness of ultraviolet irradiation in improving the capacitive performance of high‐temperature polymer dielectrics. These findings provide a novel paradigm for the rational design of high‐temperature polymer dielectrics for high‐efficiency energy storage. [ABSTRACT FROM AUTHOR]

Dielectric elastomer actuator (DEA) is considered as an ideal artificial muscle with soft and light in nature, widespread application in soft robotics and sensors. Dielectric elastomer (DE), the core component of DEA, with high output force and large actuation strain under relatively low driving electric field is critical for high‐performance DEA. However, the widely used VHB series (3M) DE suffered from very large pre‐strain and high driving voltage to get their high actuation performance, limiting their scope of application. In this work, the DEs with good mechanical and dielectric properties were prepared via UV curing method consisting of acrylic acid (AA) with strong polar groups as functional monomer, n‐butyl acrylate (BA) as soft monomer and urethane acrylate as cross‐linker (c‐p(BA‐AA)). The c‐p(BA‐AA) DE films obtained the simultaneous increasing of dielectric constant and breakdown strength with the increasing content of AA, which guaranteed the good actuation performance. The c‐p(BA‐AA) film exhibited excellent actuating performance (44.11% actuation strain at 45 kV/mm) without pre‐strain. Besides, a simple linear actuator based on the c‐p(BA‐AA) film could easily output weight that is tens of times of its own active weight (654.1 mN/g at 30 kV/mm). [ABSTRACT FROM AUTHOR]

As a natural renewable material, wood has good environmental characteristics and is widely used in the fields of architecture, landscapes, furniture and other fields. At present, as the main source of wood, artificial rapid forests generally have disadvantages such as loose structure, low density, low strength, poor size stability, etc., and are prone to deterioration due to external factors. The research on the improvement of the improvement in the improvement of wood antiseptic, hydrophobic, optical resistance, and flame retardant in recent years was reviewed, in order to provide guidance for the combination of wood durable functional combination. [ABSTRACT FROM AUTHOR]

Increasing the actuation characteristics of dielectric elastomer actuators (DEAs) under low electric field strength without compromising the elasticity and breakdown strength is still one of the great challenges in application field. Herein, we propose a simple, efficient, and controllable strategy to prepare dielectric elastomers with intrinsically good integrated properties by introducing styrene ethylene butylene styrene (SEBS) in thermoplastic polyurethane (TPU). Combined with experiments and molecular dynamics simulation, we find that the SEBS is uniformly dispersed in TPU matrix and a good interface structure is formed by pi–pi interaction and entanglement. The above characteristics lead to the destruction of the hydrogen bond network of TPU and the formation of single aggregation structure. Consequently, much decreased Young's modulus (Y) and enhanced breakdown field (Ebr) are achieved. Especially, when the content of SEBS is 4.76 wt%, the blend shows a desirable Y of 2.4 MPa and a much improved Ebr (118 kV mm−1), which is about 59% lower and 42% higher than those of TPU, respectively. As a result, the maximum electrical strain area of the dielectric blend elastomer reaches 4.7%, which is 250% higher than that of pure TPU under the same electric field strength. [ABSTRACT FROM AUTHOR]