Jiang Yu, Ye Dong, Li Aokang, Zhang Bo, Han Wenhu, Niu Xuechen, Zeng Mingtao, Guo Lianbo, Zhang Guanjun, Yin Zhouping, Huang YongAn
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Flexible Electronics Research Center, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Proc Natl Acad Sci U S A. 2024 May 28;121(22):e2402135121. doi: 10.1073/pnas.2402135121. Epub 2024 May 21.
Seamless integration of microstructures and circuits on three-dimensional (3D) complex surfaces is of significance and is catalyzing the emergence of many innovative 3D curvy electronic devices. However, patterning fine features on arbitrary 3D targets remains challenging. Here, we propose a facile charge-driven electrohydrodynamic 3D microprinting technique that allows micron- and even submicron-scale patterning of functional inks on a couple of 3D-shaped dielectrics via an atmospheric-pressure cold plasma jet. Relying on the transient charging of exposed sites arising from the weakly ionized gas jet, the specified charge is programmably deposited onto the surface as a virtual electrode with spatial and time spans of ~mm in diameter and ~μs in duration to generate a localized electric field accordantly. Therefore, inks with a wide range of viscosities can be directly drawn out from micro-orifices and deposited on both two-dimensional (2D) planar and 3D curved surfaces with a curvature radius down to ~1 mm and even on the inner wall of narrow cavities via localized electrostatic attraction, exhibiting a printing resolution of ~450 nm. In addition, several conformal electronic devices were successfully printed on 3D dielectric objects. Self-aligned 3D microprinting, with stacking layers up to 1400, is also achieved due to the electrified surfaces. This microplasma-induced printing technique exhibits great advantages such as ultrahigh resolution, excellent compatibility of inks and substrates, antigravity droplet dispersion, and omnidirectional printing on 3D freeform surfaces. It could provide a promising solution for intimately fabricating electronic devices on arbitrary 3D surfaces.
在三维（3D）复杂表面上实现微结构与电路的无缝集成具有重要意义，正推动着许多创新型3D弯曲电子器件的出现。然而，在任意3D目标上进行精细特征图案化仍然具有挑战性。在此，我们提出一种简便的电荷驱动电流体动力学3D微打印技术，该技术可通过大气压冷等离子体射流在几种3D形状的电介质上对功能墨水进行微米甚至亚微米级的图案化。依靠弱电离气体射流产生的暴露位点的瞬态充电，特定电荷被可编程地沉积到表面上，形成直径约为毫米、持续时间约为微秒的空间和时间跨度的虚拟电极，从而相应地产生局部电场。因此，具有广泛粘度范围的墨水可通过局部静电吸引直接从微喷孔中抽出，并沉积在曲率半径低至约1毫米的二维（2D）平面和3D曲面上，甚至沉积在狭窄腔体的内壁上，显示出约450纳米的打印分辨率。此外，还成功地在3D电介质物体上打印了几种共形电子器件。由于带电表面，还实现了高达1400层的自对准3D微打印。这种微等离子体诱导的打印技术具有诸多优点，如超高分辨率、墨水与基板的优异兼容性、反重力液滴分散以及在3D自由曲面的全向打印。它可为在任意3D表面紧密制造电子器件提供一个有前景的解决方案。
