Assembly Mechanism Investigation and Theoretical Framework Development of Magnetorheological Emulsions for Low Power Energy Dampers

为了保护建筑物免受地震振动和残肢免受运动的影响，开发能够安全有效地消散这些力的能量的材料至关重要。磁流变液（MRF）是油中磁性颗粒的混合物，在磁场下形成链。MRF链抵抗由于振动或冲击而断裂，而是将该能量释放为热量，从而减少对周围结构或生物材料的机械损伤。然而，典型的MRF需要大量的功率来维持高磁场。这是一个挑战，因为在地震期间无法获得电力或用于假肢的可穿戴高功率电池的安全性差。该奖项旨在开发一种基于水包油乳液的新型MRF，该乳液可以在较低磁场下实现更好的能量耗散，使用更少的功率。在MRF配方的关键因素，以及MRF链结构和整体性能的实验和理论之间的关系进行了探讨。该奖项的结果不仅将提高基础设施对自然灾害的抵御能力，并提高截肢者的生活质量，还将支持研究生沿着他们走向STEM职业生涯的指导。 耗散能量的材料对于各种各样的工程问题都是必要的，例如承受地震振动或人体运动的影响。需要新材料来提高地震弹性和假肢的舒适度。为了满足这一需求，磁流变液（MRF）可以用作粘滞阻尼器的一部分，以安全有效地耗散大量能量。 MRF是磁性颗粒分散体，当受到磁场时，形成链并抵抗流动。MRF的采用在很大程度上受到限制，这是由于大规模或身体上应用的不可接受的功率要求。该奖项研究了一种用于MRF的新的基于乳液的配方，以降低MRF的功率要求。结合实验和理论的方法将被用于与目标（1）确定的关键参数，管理MRF乳液的性能，（2）可视化磁化状态MRF乳液形态，和（3）开发一个基本框架，以概括的现象。该奖项旨在改善基础设施和假肢设备，同时为研究生提供STEM指导和经验。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

To protect buildings from earthquake vibrations and residual limbs from the impact of movement, it is critical to develop materials that can dissipate the energy of these forces safely and effectively. Magnetorheological fluids (MRFs) are mixtures of magnetic particles in oil that form chains under a magnetic field. MRF chains resist being broken up due to vibration or impact, instead releasing that energy as heat, reducing the mechanical damage to surrounding structural or biological material. Typical MRFs, however, require large amounts of power to maintain a high magnetic field. This is a challenge due to inaccessible power during an earthquake or poor safety of wearable high-power batteries for prosthetics. This award seeks to develop a new type of MRF based on oil-in-water emulsions that can achieve better energy dissipation at lower magnetic fields, using significantly less power. The critical factors in MRF formulation will be explored as well as the relationship between MRF chain structure and overall performance both experimentally and theoretically. The results of this award will not only improve infrastructure resiliency to natural disasters as well as improve the quality of life of amputees but will also support the mentorship of graduate students along their path towards STEM careers. Materials which dissipate energy are necessary for a wide variety of engineering problems, such as to withstand seismic vibrations or the impact of human motion. New materials are needed to improve earthquake resiliency and prosthetic limb comfort. To address this need, magnetorheological fluids (MRFs) can be used as part of viscous dampers to dissipate large amounts of energy safely and effectively. MRFs are magnetic particle dispersions that, when subjected to a magnetic field, form chains and resist flow. The adoption of MRFs has been limited in large part due to unacceptable power requirements for large-scale or on-body applications. This award investigates a new emulsion-based formulation for MRFs to reduce the MRF power requirement. A combined experimental and theoretical approach will be used with the objectives of (1) determining the key parameters that govern the performance of MRF-emulsions, (2) visualizing the magnetized state MRF-emulsion morphology, and (3) developing a fundamental framework to generalize the phenomena. This award enables the improvement of infrastructure as well as prosthetic devices while also providing STEM mentorship and experience for graduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.