Microrheological study of complex fluids traces its roots to the work of the botanist Robert Brown in the early nineteenth century. Indeed, passive microrheology and Brownian motion are one and the same. Once thought to reveal a fundamental life force, the phenomenon was ultimately leveraged by Einstein in proof of the atomic nature of matter (Haw 2006). His work simultaneously paved the way for modern-day passive microrheology by connecting observable particle motion—diffusion—to solvent properties—the viscosity—via the well-known Stokes–Einstein relation. Advances in microscopy techniques in the last two decades have prompted extensions of the original model to generalized forms for passive probing of complex fluids. In the last decade, active microrheology has emerged as a means by which to interrogate the nonequilibrium behavior of complex fluids, in particular, the non-Newtonian rheology of dynamically heterogeneous and microscopically small systems. Here we review theoretical and computational appro...

中文翻译：

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主动和被动微流变学：理论与模拟

复杂流体的微流变学研究可追溯到 19 世纪初植物学家罗伯特·布朗的工作。事实上，被动微流变学和布朗运动是一回事。一旦被认为揭示了一种基本的生命力，爱因斯坦最终利用这一现象来证明物质的原子性质（Haw 2006）。他的工作同时通过著名的斯托克斯-爱因斯坦关系将可观察到的粒子运动——扩散——与溶剂特性——粘度联系起来，为现代被动微流变学铺平了道路。过去二十年显微技术的进步促使原始模型扩展到复杂流体被动探测的广义形式。在过去的十年里，主动微流变学已经成为一种研究复杂流体的非平衡行为的手段，特别是动态异质和微观小系统的非牛顿流变学。在这里，我们回顾了理论和计算应用...