DMREF/Collaborative Research: Acoustically Transformative Materials

非技术总结许多研究都集中在开发用于常规声学应用的材料上，例如超声成像、隔音和地质测井。 然而，主动响应声音并同时改变其声学和光学特性的材料的设计仍处于起步阶段。 该项目的目标是设计声学响应材料，当它们与声波相互作用时，改变它们的化学结构，物理特性和物体形状，从而实现声学特性的主动调制，包括声速，衰减和声子带隙。 如果与电磁辐射相比，声波具有独特的物理特性，因为它们容易传播通过光学不透明材料，包括液体、固体和凝胶（例如，人体），其中物理上或生理上禁止直接施加常规刺激，例如光和电场。 这使得能够非侵入性地询问各种材料特性和远程激活各种机械化学过程。 此外，与电磁辐射类似，声音可以在空间和时间上聚焦。 这为以时间控制、顺序的方式执行局部修改提供了有趣的机会。 这些材料可用于声学光刻和自我修复的材料工程以及包括非侵入性手术、诊断和药物递送的生物医学应用。该项目的目标是开发一种新的材料设计方向，其中材料特性的根本变化是由声波激活的，同时改变宏观物体的声学，光学和几何特性。 研究活动追求三个战略目标。 首先，发展对复杂大分子的多尺度结构与这些分子介观块组装的材料的机械性能之间的层次相关性的基本理解。 理论研究将为合成具有非常广泛的弹性，强度和韧性的材料提供指导，这些材料目前在传统聚合物体系中不可用。 其次，研究声波与刺激响应聚合物系统的相互作用，并探索不同的激活机制，改变密度，模量，压缩性和形状。 理解声学触发的材料特性变化与声学特性相应变化之间的反馈是这一提议的智力挑战。 第三，创造一种新型材料，可以以可编程和时间分辨的方式使用声场进行远程激活，驱动和导航。 该项目的预期成果是声学变革材料，不仅对声音做出反应，而且从根本上改变其物理特性，物体尺寸以及声学和光学特性。 该项目的合作性质将确保在聚合物合成，物理实验和理论的初级研究人员的跨学科培训。 该项目还为扩大代表性不足的群体的参与和促进合作研究的基础设施提供了机会。

NON-TECHNICAL SUMMARYMany studies have focused on developing materials for conventional acoustic applications, such as ultrasound imaging, sound insulation, and geological logging. However, the design of materials that actively respond to sound and concurrently shift their acoustic and optical characteristics remains in its infancy. The goal of this project is to design acoustically responsive materials that alter their chemical structure, physical properties, and object shapes whenever they interact with sound waves enabling active modulation of acoustic properties including speed of sound, attenuation, and phononic band gaps. If compared to electromagnetic radiation, sound waves possess unique physical characteristics as they readily propagate through optically non-transparent materials, including liquids, solids, and gels (e.g., human body), where direct application of conventional stimuli, such as light and electric fields, is either physically or physiologically prohibited. This enables non-invasive interrogation of a wide range of materials properties and remote activation of various mechanochemical processes. Moreover, similar to electromagnetic radiation, sound can be focused both in space and in time. This opens intriguing opportunities to perform local modifications in a time-controlled, sequential manner. These materials may be utilized both in materials engineering for acoustic lithography and self-healing and in biomedical applications including non-invasive surgery, diagnostics, and drug-delivery. TECHNICAL SUMMARYThe project goal is to develop a new direction in materials design wherein fundamental changes in materials properties are activated by sound waves that concurrently shift acoustic, optical, and geometric characteristics of macroscopic objects. The research activities pursue three strategic objectives. First, develop fundamental understanding of hierarchic correlations between the multi-scale architecture of complex macromolecules and mechanical properties of materials assembled of these molecular mesoblocks. Theoretical studies will provide guidelines for synthesis of materials with an extraordinarily broad range of elasticity, strength, and toughness that are currently not available in conventional polymer systems. Second, study the interaction of sound waves with stimuli responsive polymer systems and explore different activation mechanisms that shift density, modulus, compressibility, and shape. Understanding the feedback between acoustically triggered changes in materials properties and the corresponding shifts in acoustic characteristics represents an intellectual challenge of this proposal. Third, create a novel class of materials that can be activated, actuated, and navigated remotely using acoustic fields in a programmable and time-resolved manner. An anticipated culmination of this project is acoustically transformative materials that not only respond to sound but also fundamentally change their physical properties, object dimensions, and acoustic and optical characteristics. The collaborative nature of this project will ensure interdisciplinary training of junior researchers in polymer synthesis, physical experiments, and theory. The project also provides opportunity for broadening participation of underrepresented groups and fostering infrastructure for collaborative research.