Engineering Viscoelasticity in Autoregulatory Nanoscale Wrinkling Bilayer Hydrogel Systems: Pressure Sensors and Thermal-Responsive Drug Delivery Systems
Engineering Viscoelasticity in Autoregulatory Nanoscale Wrinkling Bilayer Hydrogel Systems: Pressure Sensors and Thermal-Responsive Drug Delivery Systems
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DOI：
10.1021/acsanm.2c03412
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发表时间：
2022-08
影响因子：
5.9
通讯作者：
Zeynab Mousavikhamene;G. Schatz
中科院分区：
文献类型：
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作者：
Zeynab Mousavikhamene;G. Schatz
本文解释了由软而厚的水凝胶在硬而薄的皮肤上组成的双层体系的起皱行为，其中水凝胶具有粘弹性。在时间相关的力学和热机械框架下，讨论了外应力和粘弹性对纳米级皱纹形态的影响，并与水凝胶线弹性处理的相应结果进行了比较。结果表明，当模型中考虑了衬底的粘弹性时，应变速率和应变大小对纳米尺度的皱纹形态有很大的影响。因此，通过材料合成过程或材料选择来设计松弛时间起着重要作用。这对于对我们团队和其他人先前开发的自动调节湿度传感设备进行建模非常重要，其中依赖于湿度的纳米级皱纹的形成调节光通过衬底的传输或散射，从而使等离子体纳米颗粒阵列能够打开或关闭产生或消除纳米级皱纹的系统的等离子体加热。采用了三种不同的集中粘弹性模型：广义Maxwell(GM)模型、广义Kelvin-Voigt(GK)模型和Burger(BR)模型。这些模型的时间演化分析，包括与验证的高松弛时间线弹性模型的比较和与实验数据的比较，表明与GK结果最接近。最后，我们定量地展示了粘弹性模型可以访问的纳米级皱纹的形态如何通过对自动调节设备有用的量来调节穿过衬底的光透射率。这种粘弹性模型将实现更多的定量预测和设计原则，以利用响应性材料，如压力或湿度传感器或热响应性药物输送系统。
This paper explains the wrinkling behavior of a bilayer system comprised of a soft, thick hydrogel on a hard thin skin in which the hydrogel has viscoelastic properties. The role of external stress and viscoelastic properties on the morphology of nanoscale wrinkles is discussed in a time-dependent mechanical and thermomechanical framework and compared with the corresponding results from a linear elastic treatment of the hydrogel. Our results show that the strain rate and magnitude of strain have substantial impact on nanoscale wrinkle morphology when viscoelasticity of the substrate is included in the model. As such, engineering the relaxation time through the material synthesis process or material selection plays an important role. This is important to modeling an autoregulatory humidity sensing device that was previously developed by our group and others, where the formation of humidity-dependent nanoscale wrinkles tunes the transmission or scattering of light through the substrate, thereby enabling a plasmonic nanoparticle array to switch on or off plasmonic heating of the system that generates or removes the nanoscale wrinkles. Three different lumped viscoelastic models are applied: generalized Maxwell (GM), generalized Kelvin–Voigt (GK), and Burger (BR) models. Time evolution analysis of these models, including comparison with the validated linear elastic model at high relaxation time and with experimental data, shows best agreement with the GK result. Finally, we quantitatively demonstrate how the morphology of nanoscale wrinkles that is accessible to viscoelastic models can adjust the light transmission across the substrate by amounts that are useful for the autoregulatory device. This viscoelastic modeling will enable more quantitative predictions and design principles for taking advantage of responsive materials such as for pressure or humidity sensors or thermal-responsive drug delivery systems.