Guo Hongyu, Ding Qiao, Yang Yang, Du Chenguang, Nie Zhihong
Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology Nanchang 330013 P. R. China
National R&D Center for Freshwater Fish Processing, College of Life Sciences, Jiangxi Normal University Nanchang 330022 P. R. China.
RSC Adv. 2024 Oct 31;14(47):34804-34810. doi: 10.1039/d4ra03024a. eCollection 2024 Oct 29.
We report here on dual shape transformations of the same thermo-responsive hybrid hydrogel sheet under irradiation of a laser with two different wavelengths (808 nm and 450 nm). By etching the silver nanoprisms in the sheet to silver nanodiscs by using chloride ions (Cl), two areas with distinct light extinction properties are integrated in a single sheet. The conversion of photon energy to thermal energy in local areas by the silver nanoprisms or nanodiscs under laser irradiation with an appropriate wavelength heats up the sheet locally and causes a local volumetric shrinkage, and hence a volumetric mismatch in different areas in the sheet. The sheet then transforms in a specific way to accommodate this volumetric mismatch. Different patterns of silver nanoprisms and nanodiscs in the sheet are achieved by controlling the delivery patterns of the etchant Cl. We demonstrate that by designing the distribution pattern of silver nanoprisms and nanodiscs in the sheet, the same hybrid sheet transforms either to a saddle or to a helical twisted shape, while with another type of distribution pattern, it transforms either to a hoof-like or to a boat-like shape under the irradiation of a laser with a wavelength of either 808 nm or 450 nm. We point out that to program arbitrary curvature of the transformed shape of our sheet, the pattern size of silver nanoprisms and nanodiscs ( actuation area) in the sheet needs to be largely reduced, which however limits the heat generated and hence the shape transformations. Factors that affect the sheet's shape transformations are discussed and solutions are suggested to enhance its performance. The hybrid sheet may find applications in soft robotics, for example, as a robotic finger.
我们在此报告在两种不同波长（808纳米和450纳米）激光照射下，同一热响应性混合水凝胶片材的双重形状转变。通过使用氯离子（Cl）将片材中的银纳米棱柱状颗粒蚀刻成银纳米盘状颗粒，具有不同光消光特性的两个区域被整合在单片材中。在适当波长的激光照射下，银纳米棱柱状颗粒或纳米盘状颗粒将光子能量转化为局部区域的热能，从而使片材局部升温并导致局部体积收缩，进而造成片材不同区域的体积不匹配。然后，该片材以特定方式转变以适应这种体积不匹配。通过控制蚀刻剂Cl的输送模式，可以在片材中实现不同的银纳米棱柱状颗粒和纳米盘状颗粒图案。我们证明，通过设计片材中银纳米棱柱状颗粒和纳米盘状颗粒的分布图案，同一混合片材在波长为808纳米或450纳米的激光照射下，要么转变为鞍形，要么转变为螺旋扭曲形，而在另一种分布图案下，它要么转变为蹄形，要么转变为船形。我们指出，为了对我们片材转变形状的任意曲率进行编程，片材中银纳米棱柱状颗粒和纳米盘状颗粒的图案尺寸（驱动区域）需要大幅减小，然而这会限制产生的热量，从而限制形状转变。讨论了影响片材形状转变的因素，并提出了提高其性能的解决方案。这种混合片材可能在软机器人领域找到应用，例如作为机器人手指。
