微观流变学与传统的流变学有着相同的规律，属于流变学的一个分支，但它研究的是微米尺度和微升体积的流体。光镊技术已经成功应用于牛顿流体的流变学特征的研究，例如液体的黏性。然而当光镊技术用来测量复杂流体的黏弹特性时，结果不仅局限于材料的高频响应，同时会省略掉与低频行为相关的重要信息，而且用其他测量方法补充测得的低频范围的黏弹特性结果经常是没有体现出很明显的一致重叠的区域。本实验采用光镊技术并设计了简单的实验流程和数据处理方式使得流体的黏弹特性的测量达到很宽的频率范围,并且用广义朗之万方程将在两个交替开关的光阱中的捕获小球的位移和流体的黏弹特征联系起来。

Microrheology is a branch of rheology having the same principles as traditional rheology, but working on micron-scale and increased slightly the volume of fluid. Optical tweezers technology has been successfully applied to study the rheological characteristics of the Newtonian fluid, such as liquid viscosity. However, when optical tweezers are used to measuring the viscoelastic properties of complex fluids, the results are either limited to the material’s high-frequency response, discarding important information related to the low-frequency behaviour, or they are supplemented by low-frequency range measured by different techniques. The viscoelastic properties of the results are often did not reflect a clear consensus overlapping region. In this study,optical tweezers technology and the measurement of the viscoelastic properties of simple experimental procedure and data processing makes the fluid to reach a very wide frequency range. A generalized Langevin equation is used to relate the frequency-dependent moduli of the complex fluid to the time-dependent trajectory of a probe particle as it flips between two optical traps that alternately switch on and off.