Photocurable Smart Materials for Femtosecond Laser Micro/Nano‐3D/4D Printing: Toward Interdisciplinary Applications

With advances in photocurable smart materials and femtosecond (Fs) laser 3D/4D printing technologies, intelligent microsystems with tailored functionalities, high geometric complexity, and precise spatial resolution have emerged, offering significant potential for interdisciplinary applications. This review introduces Fs‐laser 3D/4D printing based on structural and functional components, highlighting inert photoresists for framework construction and stimuli‐responsive photoresists for intelligent functions. Recent progress in two‐photon polymerization‐fabricated responsive microsystems is discussed by novel actuation mechanisms, including chemically driven (pH, solvents, humidity, and sugars) and physically driven systems (temperature, magnetic fields, and electrical stimuli). Emphasis is placed on microactuators regarding material design, actuation mechanisms, and structure–function relationships. Emerging applications in actuating, sensing, micromechanical systems, and microrobotics are also highlighted. Finally, current challenges and future opportunities in smart photoresists and functional micro/nanostructures are outlined.