Javad Foroughi

Soft robotic systems require actuators that combine large deformation, mechanical robustness, and reliable operation under practical conditions. Twisted and coiled polymer (TCP) artificial muscles, typically fabricated from fibrous materials, offer high power density and large stroke; however, their reliance on elevated operating temperatures (>80°C) for high performance limits their use in temperature‐sensitive environments. Here, we report a thermoresponsive gel‐yarn composite actuator that enables actuation at reduced temperatures within TCP‐based systems. Twisted polyester yarns were functionalized with a biocompatible thermosensitive hydrogel, poly(MAA‐co‐OEGMA), forming a fiber‐gel composite architecture. Temperature‐induced swelling and deswelling of the hydrogel in cold and hot water, respectively, generated internal stresses within the yarn, which drive untwisting of the coiled structure and result in lengthwise actuation. The effect of ionic crosslinking was systematically investigated by varying FeCl ₃ concentration, with 1 M identified as the optimal condition balancing structural stiffness and actuation performance. The composite actuators exhibit isotonic free strains of up to 39% when cycled between room temperature and 50°C and work densities of up to 8.8 × 10 ^{− 3} J g ^{− 1} , with reversible and repeatable actuation behavior. Compared to conventional TCP systems, which typically operate at substantially higher temperatures, the present system achieves similar deformation but within a lower and more practical thermal range. These findings suggest that fiber‐gel composite architectures provide a viable route for tuning actuation behavior in TCP systems while maintaining compatibility with temperature‐sensitive applications.

Soft robotic cardiac sleeves are an emerging class of non-blood-contact mechanical circulatory support devices designed to augment myocardial function while avoiding direct interaction with blood. Their development addresses important limitations of conventional heart failure therapies and offers a promising strategy for physiological cardiac assistance. This Review examines the pathophysiological basis for sleeve-assisted cardiac support, recent advances in soft robotic technologies, and the key engineering and translational challenges that must be overcome for clinical implementation. Finally, we propose a translational framework to guide the future development of clinically viable soft robotic cardiac sleeves.

Soft robotic cardiac sleeves integrate advanced actuator materials, biomimetic ventricular mechanics, and emerging disease-modeling capabilities to enable translational non-blood-contact support for heart failure.

High-performance biocompatible composite materials are gaining attention for their potential in various fields such as neural tissue scaffolds, bio-implantable devices, energy harvesting, and biomechanical sensors. However, these devices currently face limitations in miniaturization, finite battery lifetimes, fabrication complexity, and rigidity. Hence, there is an urgent need for smart and self-powering soft devices that are easily deployable under physiological conditions. Herein, we present a straightforward and efficient fabrication technique for creating flexible/stretchable fiber-based piezoelectric structures using a hybrid nanocomposite of polyvinylidene fluoride (PVDF), reduced graphene oxide (rGO), and barium-titanium oxide (BT). These nanocomposite fibers are capable of converting biomechanical stimuli into electrical signals across various structural designs (knit, braid, woven, and coil). It was found that a stretchable configuration with higher output voltage (4 V) and a power density (87 μW cm⁻³) was obtained using nanocomposite coiled fibers or knitted fibers, which are ideal candidates for real-time monitoring of physiological signals. These structures are being proposed for practical transition to the development of the next generation of fiber-based biomedical devices. The cytotoxicity and cytocompatibility of nanocomposite fibers were tested on human mesenchymal stromal cells. The obtained results suggest that the developed fibers can be utilized for smart scaffolds and bio-implantable devices.