The creation of smart cities has benefited greatly from the quick advancement of sensor and actuator technology. The basis of data-driven urban environments is supported by these technologies, which seamlessly connect with the Internet of Things (IoT). This in-depth review paper explores the crucial part that sensors and actuators play in the development of smart cities, covering important topics such as technological kinds, data security, regulatory frameworks, and future possibilities. The review begins by explaining the importance of sensors and actuators in the Internet of Things (IoT) connections that serve as the framework for smart cities. Additionally, it sheds light on the wide range of sensors designed for different IoT applications as well as the variables affecting their service life, highlighting how crucial precision and durability are. Actuators are examined in detail to clarify how it might be used to create smarter cities. Actuators are the dynamic counterparts of sensors. This review discusses data security in big data exchange among actuators, legal foundations for smart city development, and key elements for creating a smart city. It highlights the benefits of advanced actuator technology and sensor integration, and emerging trends like AI-driven urban management and blockchain-enhanced data security. The paper serves as a guide for researchers, policymakers, and urban planners. The graphical abstract below illustrates the multifaceted advancements in sensor and actuator technologies, showcasing their pivotal role in shaping smarter, more sustainable cities. Graphical Abstract

The combination of brain cells and artificial intelligence (AI) is a paradigm shift in the healthcare industry that provides previously unheard-of chances for creativity and change in a variety of fields. This work is an attempt to offer a thorough examination of the confluence of AI and brain cells in healthcare, clarifying important ideas, methods, and applications that will influence medical practice and research going forward. Theis article provides an overview of AI in healthcare and looks at the wide variety of AI methods and algorithms advancing personalized medicine, therapy optimization, and disease diagnostics. It also touches upon how AI and brain cells interact, and how brain–computer interfaces (BCIs) can transform neuroscience research and human–machine interaction. It also highlights the revolutionary influence of brain cells and AI on healthcare delivery and patient care by outlining the application domains of the BCI across research fields and talking about the integration of reinforcement learning with the BCIs. It also showcases the practical applications of brain cells and AI in healthcare, ranging from prognostication and diagnostics to prosthetics and rehabilitation. This work suggests new trends and research and development opportunities in the field of brain cells and AI integration, as well as future directions in this field.