Designing Highly Polar Self-Assembled Molecular Piezoelectric Materials

摘要柔性电子技术的最新进展为轻量化设备提供了巨大的希望，使从移动计算到医疗植入物的应用成为可能。同时，对便携式能源解决方案的需求也在上升，因为集成能源存储或转换对这些技术的动力至关重要。机械能无处不在，但很难有效利用。通过在机械力和电流之间进行转换来捕获这种廉价且容易获得的能量来源，可以带来创新的进步，例如用于触摸、振动或力的自供电传感器，或柔性触摸屏。现有的用于获取机械能的材料通常不灵活、易碎、难以加工。巨大的潜在应用，加上当前材料的关键限制，迫切需要从下至上的角度来研究机械能的转换。在固态和材料化学项目的支持下，该项目侧重于对这些材料的基本理解和优化，首先是作为分子，然后是作为单分子层，然后是薄膜和器件。结果将是一个新的柔性，可压缩材料家族用于微尺度能源产生和能量收集。除了研究部分，该项目还为高中生、本科生和研究生提供纳米材料跨学科领域以及实验和计算研究相结合的培训。技术摘要：该合作项目整合了合成、表征和模拟驱动材料设计，以开发一系列用于能量收集应用的分子固体压电材料。该研究的核心假设是，基于肽和相关生物启发低聚物的构象驱动分子压电材料的定向自组装导致材料具有比现有压电材料优越得多的特性（压电响应，电学性能，柔韧性）。该项目建立在现有的合作和强有力的初步结果的基础上，预测了在外加电场中极性分子构象变化的高压电响应。该项目推进了新型电反应生物启发材料的合成、建模和表征。在每个阶段，研究人员都确定了反应性分子目标以及生产最佳层和薄膜所需的特性。这些结果有助于对生物材料机电特性的基本理解，包括被纳米级电场（如离子或偶极子）包围的凝聚态分子的精确几何形状。

Non-Technical AbstractRecent advances in flexible electronics offer tremendous promise for lightweight devices, enabling applications from mobile computing to medical implants. Simultaneously, the demand for portable energy solutions has risen, since integrated energy storage or conversion is critical to power these technologies. Mechanical energy is ubiquitous but challenging to use effectively. Capturing this inexpensive and readily available energy source by converting between mechanical force and electrical current can lead to innovative advances such as self-powered sensors for touch, vibration or force, or flexible touch screens. Existing materials used to harvest mechanical energy are often inflexible, brittle, and hard to process. The vast potential applications, coupled with key limitations of current materials, create a compelling need for a new perspective on the conversion of mechanical energy, from the bottom up. With support from the Solid State and Materials Chemistry program, this project focuses on fundamental understanding and optimizing these materials first as molecules, then as single molecular layers, and then in films and devices. The result will be a new family of flexible, compressible materials for microscale energy generation and energy harvesting. Beyond the research component, the project provides training to high school, undergraduate, and graduate students in both the interdisciplinary field of nanomaterials and the combination of experimental and computational research.Technical AbstractThis collaborative project integrates synthesis, characterization, and simulation-driven materials design to develop a family of molecular solid piezoelectric materials for energy harvesting applications. The central hypothesis underlying the research is that directed self-assembly of conformationally-driven molecular piezoelectrics based on peptides and related bio-inspired oligomers leads to materials with far superior characteristics (piezo response, electrical properties, flexibility) than current piezo materials. The project builds on an existing collaboration and strong preliminary results that predict high piezo response from conformational changes of polar molecules in an applied electric field. The project advances the synthesis, modeling, and characterization of new electroresponsive bio-inspired materials. At each stage, the research identifies responsive molecular targets as well as the properties needed to produce optimal layers and films. These results contribute to the fundamental understanding of electromechanical properties of biomaterials, including accurate geometries of molecules in the condensed phase surrounded by nanoscale electric fields, such as ions or dipoles.