GOALI: Dynamics of Ultrasound-Responsive Polymeric Systems: from Atoms to Devices

形状记忆聚合物是一类新兴的智能材料，当受到诸如热、光和磁场等外部刺激时，具有从变形的临时形状恢复到原始永久形状的能力。这些聚合物最近在许多应用中获得了极大的兴趣，包括机器人、生物医学设备和软电子。在许多此类应用中，迫切需要用更高效、更灵活的方法取代传统的触发方法来驱动聚合物。这项学术与工业联络资助机会（GOALI）将研究高强度聚焦超声作为一种新颖而有前途的刺激，具有独特的能力，可以驱动形状记忆聚合物的受控形状恢复。聚焦超声远程和局部驱动聚合物，无创且具有生物相容性。这些特性使该方法成为一种优越的候选方法，特别是在生物医学应用方面。该研究将由工业合作伙伴MedShape公司整合到工业实践中，为制造用于医疗应用的超声波敏感聚合物提供实用方法。MedShape公司将制造工业形状记忆聚合物驱动器，并提供学生实习机会。该研究奖的成果将提高美国医疗行业的核心竞争力。该奖项将支持高强度聚焦超声场下形状记忆聚合物动力学的实验和多尺度建模。该研究旨在填补在考虑声响应聚合物中与高激励水平相关的时变和非线性效应方面的知识空白。将建立一个多物理场框架，以在原子尺度上的动态变形机制与聚合物在宏观尺度上的响应之间建立桥梁。然后，该框架将与实验相结合，以有效地设计基于外在长度尺度和内在材料特性的超声响应聚合物的化学成分和晶体结构。该研究成果将揭示超声加热聚合物的声致热驱动机制，并有助于优化高强度聚焦超声场中形状记忆聚合物结构的形状固定和恢复的动态过程。研究结果还将揭示增材制造的形状记忆聚合物的几何方面如何影响聚合物在各种超声场中的动力学。在与工业合作伙伴MedShape公司的合作中，该奖项支持的研究中开发的方法将用于设计和制造具有医疗应用的新型超声响应聚合物设备。该奖项反映了美国国家科学基金会的法定使命，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。

Shape memory polymers are an emerging class of smart materials that have the ability to return from a deformed temporary shape to their original permanent shape when subjected to an external stimulus such as heat, light, and a magnetic field. These polymers have recently gained substantial interest in many applications including robotics, biomedical devices, and soft electronics. In many of these applications, there is an immediate industrial need for replacing conventional triggering methods for actuating the polymers with a more efficient and flexible method. This Grant Opportunities for Academic Liaison with Industry (GOALI) grant will investigate high-intensity focused ultrasound as a novel and promising stimulus with unique capabilities to actuate the controlled shape recovery of shape memory polymers. Focused ultrasound actuates the polymer remotely and locally, is noninvasive, and is biocompatible. These properties make the methodology a superior candidate, particularly for biomedical applications. The research will be integrated into industrial practice by the industrial partner, MedShape Inc., to provide practical approaches for the fabrication of ultrasound-sensitive polymers for medical applications. MedShape Inc. will fabricate industrial shape memory polymer actuators and provide student internship opportunities. The outcomes of this research award will increase the core competencies of U.S. medical industries.This award will support the experiments and multiscale modeling of the dynamics of shape memory polymers under high-intensity focused ultrasound fields. The research aims at filling a knowledge gap in terms of considering time-variant and nonlinear effects associated with high excitation levels in acoustic-responsive polymers. A multiphysics framework will be established to bridge the dynamical deformation mechanisms at the atomistic scale to the response of the polymer at the macroscale. This framework will then be combined with experiments to efficiently design the chemical composition and crystalline structure of ultrasound-responsive polymers, based on extrinsic length scales and intrinsic material properties. The output of the research effort will unravel the unknown mechanisms of acoustic-induced thermal actuation, by which ultrasound waves heat polymers, and help in optimizing the dynamic processes of shape fixation and recovery of shape memory polymer structures in high-intensity focused ultrasound fields. The findings will also uncover how the geometrical aspects of the additively manufactured shape memory polymers will affect the dynamics of the polymer in various ultrasound fields. In collaboration with the industrial partner, MedShape Inc., the approach developed in the research supported by this award will be utilized to design and fabricate novel ultrasound-responsive polymer-based devices with medical applications.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.