Chapters authored
Smart Hydrogel-Based Actuators and Artificial Muscles: Emerging Frontiers in Soft Robotics
Smart hydrogel-based actuators have emerged as a prominent class of soft robotic components due to their intrinsic compliance, biocompatibility, and multi-stimuli responsiveness. These materials can undergo reversible deformations—including bending, twisting, swelling, contraction, and locomotion—when exposed to thermal, electrical, chemical, magnetic, or optical stimuli, enabling close emulation of natural muscle behavior. Owing to their high water content and tunable polymer networks, hydrogel actuators offer safe and adaptive interfaces for biological and human-centric applications. Recent advances in polymer chemistry, nanocomposite reinforcement, additive manufacturing, and biohybrid design have significantly expanded the performance envelope of hydrogel actuators. Innovations in fabrication strategies such as 3D/4D printing, micro-patterning, and layered architectures have enabled precise control over actuation modes, response speed, and force generation. As a result, hydrogel actuators are increasingly explored in artificial muscles, biomedical microrobots, implantable devices, wearable systems, and intelligent soft robotic platforms. This chapter presents a comprehensive review of hydrogel fundamentals, actuation mechanisms, material systems, and fabrication approaches, followed by an overview of key application domains. Comparative benchmarking with alternative artificial muscle technologies is provided, highlighting performance trade-offs in strain, stress output, efficiency, and controllability. Emerging integration of sensing and self-feedback functionalities is also discussed. Finally, critical challenges—including dehydration, limited mechanical strength, energy efficiency, and scalability—are examined, with future perspectives emphasizing biohybrid systems, nanocomposite hydrogels, and 4D-printed architectures for next-generation intelligent soft robots. If you want, I can adapt this for a PhD thesis chapter, Springer/Elsevier book chapter, or IEEE-style review with references added.
Part of the book: Hydrogels