Femtosecond Laser 4D Printing of Light‐Driven Intelligent Micromachines

• Published in: Advanced functional materials 2023-03, Vol.33 (11), p.n/a
• Main Authors: Deng, Chunsan, Liu, Yuncheng, Fan, Xuhao, Jiao, Binzhang, Zhang, Zexu, Zhang, Mingduo, Chen, Fayu, Gao, Hui, Deng, Leimin, Xiong, Wei
• Format: Article
• Language: English
• Subjects: 4D printing; Actuation; Adaptive optics; Bionics; Carbon nanotubes; Electromagnetic absorption; femtosecond laser direct writing; Hydrogels; intelligent micromachines; Light; light stimulation; Materials science; Metamaterials; Microrobots; Morphing; Printing; Structural design; Thermal conductivity
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202211473

Intelligent micromachines that respond to external light stimuli have a broad range of potential applications, such as microbots, biomedicine, and adaptive optics. However, artificial light‐driven intelligent micromachines with a low actuation threshold, rapid responsiveness, and designable and precise 3D transformation capability remain unachievable to date. Here, a single‐material and one‐step 4D printing strategy are proposed to enable the nanomanufacturing of agile and low‐threshold light‐driven 3D micromachines with programmable shape‐morphing characteristics. The as‐developed carbon nanotube‐doped composite hydrogel simultaneously enhanced the light absorption, thermal conductivity, and mechanical modulus of the crosslinked network, thus significantly increasing the light sensitivity and response speed of micromachines. Moreover, the structural design and assembly of asymmetric microscale mechanical metamaterial unit cells enable the highly efficient additive nanomanufacturing of 3D shape‐morphable micromachines with large dynamic modulation and spatiotemporal controllability. Using this strategy, the world's smallest artificial beating heart with programmable light‐stimulus responsiveness for the cardiac cycle is successfully printed. This 4D printing method paves the way for the construction of multifunctional intelligent micromachines for bionics, drug delivery, integrated microsystems, and other fields. A composite nano hydrogel material and one‐step 4D printing strategy are presented to enable the nanomanufacturing of agile and low‐threshold light‐driven 3D micromachines with programmable shape‐morphing characteristics. The intelligent micromachines with high light‐stimuli response speed, tunable actuation response, high mechanical modulus, and excellent mechanical output performance are designed and manufactured based on this strategy.