ABSTRACT
Innovations of magnetic hydrogels have revolutionized a broad range of biomedical, sensing, and soft robotic applications. Magnetic hydrogel-based sensors constitute a class of smart sensing devices activated by magnetism and magnetic forces with emphasized roles in environmental monitoring and healthcare technologies. Unlike carbohydrates and elastomers, hydrogels are attractive for advanced modifications due to their exclusive properties such as three-dimensional (3D) porous structures, good mechanical strength, high water content, and tailorable behavior. The attractive characteristics of hydrogels enable them to introduce chemical functionalities and incorporate various functional nanomaterials such as magnetic nanoparticles into their extremely porous networks. The integration of the Internet of Things (IoT) with magnetic hydrogel-based sensors could unlock a new wave of cutting-edge technologies, providing real-time monitoring of health and environmental information to patients, clinicians, and inspectors. This chapter covers the preparative methods of magnetic hydrogels with an emphasis on magnetic nanomaterials as the magnetic component. Advances of magnetic hydrogels in the development of biomedical devices (e.g., wearable biomedical devices, soft robotic sensors, actuators) and environmental sensors are presented. Finally, this chapter discusses the challenges and future opportunities of magnetic hydrogels in emerging soft robotic technology and sensors for biomedical and environmental applications.
