Collaborative Research: Acoustic Tweezing Rheometry of Biological Fluids

CBET 1438569/1438567该奖项由化学，生物工程，环境和运输系统部门的颗粒和多相过程（PMP）计划授予（CBET，工程理事会），由生物基础设施部的生物研究仪器开发（IDBR）计划共同资助测量生物材料和其他复杂流体（如聚合物液体）的物理和机械特性对科学家和工程师提出了特殊的挑战。 这些材料的性质可由于材料与固体壁（例如容纳材料的容器的壁）之间的接触而改变。 该合作项目涉及开发一种新的设备和新的方法来测量流体或固体的流变特性，避免样品和固体壁之间的接触。 该方法被称为声学镊子流变学，它使用声悬浮将小样品自由悬浮在空气或水中，同时对材料施加力使其变形。 然后，该设备通过记录样品形状随时间的变化来读取材料的响应。 通过将样品的形状与作为项目一部分进行的计算机模拟进行比较，可以推断出材料的流变特性。 这种新仪器将在各种科学和工程学科中找到应用。声学镊子流变学将用于测量活性聚合物和生物流体以及软组织的特性，而不会出现污染，生物活化或由于与固体壁接触而凝胶化等伪影。通过分析研究和计算机模拟，将建立一个非接触测量材料常数的模型。 声学镊子技术将被开发和验证的粘弹性流体的材料特性的测量。 该方法将应用于生物液体和软组织，包括凝固过程中的全血和胶原蛋白凝胶。 将广泛传播成果，包括向可能受益于新方法的生物界进行宣传。

CBET 1438569/1438567This award by the Particulate and Multiphase Processes (PMP) program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems (CBET, Engineering Directorate), is co-funded by the Instrument Development for Biological Research (IDBR) program in the Division of Biological Infrastructure (BIO Directorate).Measuring the physical and mechanical properties of biological materials and other complex fluids such as polymeric liquids poses special challenges for scientists and engineers. The properties of these materials can change owing to the contact between the material and solid walls, such as the walls of a container holding the material. This collaborative project involves the development of a new device and new method to measure the rheological properties of fluids or solids that avoid contact between the sample and solid walls. The method is called acoustic tweezing rheometry, and it uses acoustic levitation to hold a small sample freely suspended in air or water while applying a force on the material that causes it to deform. The device then reads the response of the material by recording changes in the shape of the sample as a function of time. By comparing the shape of the sample with computer simulations carried out as part of the project, the rheological properties of the material can be deduced. This new instrument will find applications in a diverse array of science and engineering disciplines.Acoustic tweezing rheometry will be used to measure properties of active polymeric and biological fluids and soft tissue without artifacts such as contamination, biological activation or gelation due to contact with solid walls. A model will be developed for noncontact measurement of material constants through analytical studies and computational simulation. The acoustic tweezing technique will be developed and validated for measurement of material properties of viscoelastic fluids. The method will be applied to biological fluids and soft tissue, including whole blood during coagulation and collagen gel. Results will be disseminated broadly, including outreach to the biological communities that could benefit from the new method.