Flexible Pressure Sensors Enhanced by 3D-Printed Microstructures.

3D printing has revolutionized the development of flexible pressure sensors by enabling the precise fabrication of diverse microstructures that significantly enhance sensor performance. These advancements have substantially improved key attributes such as sensitivity, response time, and durability, facilitating applications in wearable electronics, robotics, and human-machine interfaces. This review provides a comprehensive analysis of the sensing mechanisms of these sensors, emphasizing the role of microstructures, such as micro-patterned, microporous, and hierarchical designs, in optimizing performance. The advantages of 3D printing techniques, including direct and indirect fabrication methods, in the creation of complex microstructures with high precision and adaptability are highlighted. Specific applications, including human physiological signal monitoring, motion detection, soft robotics, and emerging applications, are explored to demonstrate the versatility of these sensors. Additionally, this review briefly discusses key challenges, such as material compatibility, optimization difficulties, and environmental stability, as well as emerging trends, such as the integration of advanced technologies, innovative designs, and multidimensional sensing as promising avenues for future advancements. By summarizing recent progress and identifying opportunities for innovation, this review provides critical insights into bridging the gap between research and real-world applications, helping to accelerate the evolution of flexible pressure sensors with sophisticated 3D-printed microstructures.