4D Direct Laser Writing of Submerged Structural Colors at the Microscale. Issue 2 (16th November 2022)

• Record Type: Journal Article
• Authors: Liu, Bingrui; Dong, Bin; Xin, Chen; Chen, Chao; Zhang, Leran; Wang, Dawei; Hu, Yanlei; Li, Jiawen; Zhang, Li; Wu, Dong; Chu, Jiaru
• Is Part Of: Small. Volume 19:Issue 2(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-16
• Subjects: direct laser writing -- femtosecond lasers -- four‐dimensional printing -- pH‐responsive hydrogels -- structure colors; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202204630
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Biomimetic stimuli‐responsive structure colors (SCs) can improve the visualization and identification in the micro functional structure field such as information encryption/decryption and smart actuators. However, it is still challenging to develop the ability to 4D print arbitrary submerged colorful patterns with stimuli‐responsive materials at the microscale. Herein, a hydrogel photoresist with feature resolution (98 nm) for the fabrication of 4D microscopic SCs by the femtosecond direct laser writing method is developed. The 4D printed woodpile SCs are grouped as pixel palettes with various laser parameters and they spanned almost the entire color space. The coloring mechanism of diffraction gratings is not only investigated by optics microscopy and spectroscopy but also supported by simulation. Moreover, the 4D printed hydrogel‐integrated amphichromatic fish constructions and pixelated painting can visually discolor reversibly by regulating the solution pH. This finding promises an ideal coloring method for sensors, anti‐counterfeiting labels, and transformable photonic devices. Abstract : A hydrogel photoresist with high feature resolution was developed for the fabrication of 4D microscopic structure colors by the femtosecond direct laser writing. The 4D printed hydrogel‐integrated amphichromatic fish constructions and pixelated painting can visually discolor reversibly by regulating the solution pH. This finding promises an ideal coloring method for sensors, anti‐counterfeiting labels and transformable photonic devices.