Ultrasound adds the third dimension to wearable sensors.

Conventional robotic systems are built with rigid materials to deal with large forces and predetermined processes. Soft robotics, however, is an emerging field seeking to develop adaptable robots that can perform tasks in unpredictable environments and biocompatible devices that close the gap between humans and machines. Dielectric elastomers (DEs) have emerged as a soft actuation technology that imitates the properties and performance of natural muscles, making them an attractive material choice for soft robotics. However, conventional DE materials suffer from electromechanical instability (EMI), which reduces their performance and limits their applications in soft robotics. This review discusses key innovations in DE artificial muscles from a material standpoint, followed by a survey on their representative demonstrations of soft robotics. Specifically, we introduce modifications of DE materials that enable large strains, fast responses, and high energy densities by suppressing EMI. Additionally, we examine materials that allow variable stiffness and self‐healing abilities in DE actuators. Finally, we review dielectric elastomer actuator (DEA) applications in soft robotics in four categories, including automation, manipulation, locomotion, and human interaction.

Existing haptic actuators are often rigid and limited in their ability to replicate real-world tactile sensations. We present a wearable haptic artificial muscle skin (HAMS) based on fully soft, millimeter-scale, multilayer dielectric elastomer actuators (DEAs) capable of significant out-of-plane deformation, a capability that typically requires rigid or liquid biasing. The DEAs use a thickness-varying multilayer structure to achieve large out-of-plane displacement and force, maintaining comfort and wearability. Experimental results demonstrate that HAMS can produce complex tactile feedback with high perception accuracy. Moreover, we show that HAMS can be integrated into extended reality (XR) systems, enhancing immersion and offering potential applications in entertainment, education, and assistive technologies.

Premature debonding failure is a serious problem for reinforced concrete (RC) members strengthened with carbon fibre reinforced polymer (CFRP) laminates. Although various mechanical anchorage systems have been proposed to prevent debonding between CFRP and RC beam, these systems are generally difficult to apply to narrow RC beams due to width limitations. In this study, to resolve the debonding problems, an innovative hybrid end-anchorage system was developed, which achieves self-locking of the externally bonded CFRP sheets. To achieve this hybrid anchorage, both ends of the CFRP sheet were wrapped around twin rods, and the sheet was bonded along the length of the tension side of the beam. Then, to fix the twin rods, two L-shaped brackets were bolted on the side of the beams. In total, five RC beam specimens with rectangular cross sections were prepared and strengthened in different manners and then subjected to four-point bending tests. The enhancement effect of the hybrid anchorage on the flexural behaviour of the strengthened RC beams was validated. With a larger CFRP width, the strengthening effect was more notable, especially when the concrete strength grade was higher. Existing formulas were used to calculate the characteristic moments of the strengthened RC beams, including the cracking moment, yield moment and ultimate moment, and the applicability of the models was examined. Based on the test results, the formula for the ultimate moment of the specimens with the end anchorage requires further investigation.

Infrared information encryption is an emerging technique that leverages infrared (IR) radiation for secure data transmission. However, current IR encryption strategies fail to achieve real-time and precise data transmission, increasing the risk of information leakage. Here, utilizing a bistable adhesion polymer as a transfer medium, a multilayer relaxor ferroelectric polymer (RFP) stack is fabricated without additional thermal loads. An 8-layer RFP stack generates a rectangular temperature wave upon the application of an electric field. Its temperature rapidly increases from 22.1 °C to 26.3 °C and remains above 26 °C for over 8 s under an applied electric field of 80 MV/m at 0.01 Hz. Due to the instantaneous electrocaloric effects (temperature change rate up to10 ^-8 s/K) upon voltage application, the stack enables a real-time and programmable IR information encryption and decryption strategy. This approach highlights the potential of IR-based communication for secure data transmission, with applications in confidential messaging and optical encryption systems.

This work demonstrates a multi-line refreshable Braille device (RBD) employing a hybrid actuation system composed of a variable stiffness polymer (VSP) substrate integrated with stretchable Joule heating electrodes (JHE) and a micropump. The electrodes feature a multilayer structure comprising carbon nanotubes (CNT) and silver nanowires (AgNW), optimized for electrical conductivity, mechanical resilience, and thermal uniformity. The multilayer is laser-patterned into individual serpentine traces to enable localized and efficient Joule heating to soften the VSP membrane above its glass transition temperature (∼50°C) within 2 seconds, thus allowing pneumatic pressure to raise tactile pins by >0.5 mm for Braille reading. The Joule-heating electrodes require ∼0.027 W per dot, corresponding to a total energy of ∼0.04 J per dot per actuation, including the micropump, which is low compared to existing technologies. Comprehensive electrode characterization identifies an optimal resistance range (5.5 to 6.9 kΩ) for uniform and stable heating. Thermal analysis reveals a critical upper power limit (∼0.04 W), beyond which the AgNW structure undergoes degradation. A fully integrated 4 × 10 cell prototype demonstrates robust mechanical performance and reliable multi-line refresh capabilities over hundreds of cycles. These findings provide a promising foundation for combining deformable polymers and stretchable conductive electrodes in advanced tactile interfaces, advancing compact, energy-efficient multi-line Braille displays. Areas for future refinement are discussed to enhance the practical usability and reliably of the RBD devices.