The lipid membrane surrounding every living cell is a complex structure which has inspired decades of research into its biological functions and material properties. It might seem that a property of lipid membranes as fundamental as viscosity would be well-characterized and predictable. However, membrane viscosity has proven surprisingly challenging to measure. Approximate values and even relative viscosities in ordered and disordered phases have been published, but we still lack systematic measurements showing how the viscosities of complex lipid mixtures vary with their composition. For example, most experimental results suggest that viscosity of cell plasma membranes increase with cholesterol content, but predicting the magnitude of this increase is not possible.

围绕每个活细胞的脂质膜是一个复杂的结构，这激发了数十年来对其生物学功能和材料特性的研究。似乎脂膜的基本特性如粘度将被很好地表征和预测。然而，膜粘度已经证明难以测量。已经公布了有序和无序相的近似值甚至相对粘度，但我们仍然缺乏系统的测量方法来显示复杂脂质混合物的粘度如何随其组成而变化。例如，大多数实验结果表明细胞质膜的粘度随胆固醇含量的增加而增加，但无法预测这种增加的幅度。