CAREER: Superelastic Organic Semiconductors (SOSs): A New Class of Molecular Crystals of Responsive Shape Memory

职业：超弹性有机半导体（SOS）：一类新型响应形状记忆分子晶体

• 批准号: 1941323
• 负责人: Kejie Zhao
• 金额: $ 51.13万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1941323&HistoricalAwards=false
• 关键词: CAREER; Superelastic; Organic; Semiconductors; SOSs

This Faculty Early Career Development (CAREER) grant will promote fundamental understanding of the responsive shape memory effect in a new class of superelastic organic semiconductors (SOSs). The shape memory effect can be illustrated by the ability of a material to remember and recover a programmed shape via thermal and mechanical input. Superelasticity refers to the ability of a material to recover a large amount of mechanical deformation at a given temperature. Superelasticity in organic crystals - through interconvertible phase changes - is a recently discovered materials phenomenon. This discovery will likely breed a new research field on polymorphic engineering of molecular crystals, providing a way of overcoming the intrinsic fragility (brittleness) of organic crystals in deformable electronics. Polymorphism is the ability of a material to exist in more than one crystal structure (ordered molecular arrangement). This award explores the fundamental relationship between those structural states and the functionalities of superelasticity, ferroelasticity, and shape memory. Electronic devices with SOSs as active layers can respond to environmental stimuli without additional circuits and find a variety of applications such as remote sensing, memory devices, and programmable electronics. SOSs are also intriguing when it comes to their mechanically and thermally tunable electrical and optical properties. With the potential to create new forms of electronic and optical devices, it is vital to understand and rationalize the mechanics of superelastic organic semiconductors. This research project will both theoretically and experimentally analyze the deformability and shape memory in organic semiconductors under mechanical and thermal load and further understand the fundamental relationship between the mechanical, thermal, and optoelectronic properties of SOSs. The research will leverage the educational and outreach activities based on new curriculum development integrating data sciences, engineering education for K-12 students through an existing collaboration with Women in Engineering Program at Purdue, and engagement of underrepresented groups in engineering sciences.The specific goal of the research is to understand the mechanics and molecular mechanism of superelasticity, ferroelasticity, and shape memory effect in a new class of organic semiconductors using multi-scale theoretical modeling and experimentation approaches. The research will (i) understand the cooperative molecular mechanism underlying the deformability and shape memory effect in the solid-state molecular crystal, (ii) understand the thermodynamics, kinetics, and stress profiles along the trajectory of the martensitic transition under the thermal and mechanical load, (iii) understand the molecular kinetics and deformation twinning/detwinning in organic crystals responsible for the superelasticity, ferroelasticity, and shape memory effect, and (iv) establish the structure-property relationship by understanding the mechanical, electronic, optical, and thermal properties of SOSs for the use in optoelectronics. Overall, the research project is to address a grand challenge in the fundamental understanding of molecular structures of macroscopic and reversible deformation in response to external stimuli. The fundamental understanding of superelasticity/ferroelasticity in organic crystals will create new knowledge about the martensitic phase transition in solid-state molecules. Such knowledge can open new avenues for rapid, reversible modulation of electronic and optical properties by means of molecular design.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.

这项教师早期职业发展（Career）资助将促进对新型超弹性有机半导体（SOSs）响应形状记忆效应的基本理解。形状记忆效应可以通过材料通过热和机械输入记忆和恢复程序形状的能力来说明。超弹性是指材料在给定温度下恢复大量机械变形的能力。有机晶体中的超弹性-通过相互转换的相变-是最近发现的材料现象。这一发现可能会催生一个新的研究领域，即分子晶体的多态工程，为克服可变形电子产品中有机晶体的固有脆弱性（脆性）提供一种方法。多态是一种物质以一种以上的晶体结构（有序分子排列）存在的能力。该奖项探讨了这些结构状态与超弹性、铁弹性和形状记忆功能之间的基本关系。使用sos作为有源层的电子设备可以响应环境刺激而无需额外的电路，并且可以找到各种应用，例如遥感，存储设备和可编程电子设备。当涉及到它们的机械和热可调谐的电学和光学特性时，SOSs也很有趣。由于有可能创造新的电子和光学器件形式，理解和合理化超弹性有机半导体的力学是至关重要的。本课题将从理论和实验两方面分析有机半导体在机械和热载荷下的可变形性和形状记忆性，进一步了解有机半导体的机械、热、光电性能之间的基本关系。该研究将利用基于新课程开发的教育和推广活动，整合数据科学，通过与普渡大学女性工程项目的现有合作，为K-12学生提供工程教育，并参与工程科学中代表性不足的群体。本研究的具体目标是利用多尺度理论建模和实验方法，了解一类新型有机半导体的超弹性、铁弹性和形状记忆效应的力学和分子机制。该研究将(1)了解固态分子晶体中可变形性和形状记忆效应的协同分子机制；(2)了解热载荷和机械载荷下马氏体转变轨迹的热力学、动力学和应力分布；(3)了解有机晶体中导致超弹性、铁弹性和形状记忆效应的分子动力学和变形孪晶/脱孪晶。（iv）通过了解用于光电子学的SOSs的机械、电子、光学和热性能，建立结构-性能关系。总的来说，该研究项目旨在解决一个巨大的挑战，即对外部刺激下宏观和可逆变形的分子结构的基本理解。对有机晶体中超弹性/铁弹性的基本认识将为固体分子中的马氏体相变提供新的认识。这些知识可以为通过分子设计快速、可逆地调制电子和光学性质开辟新的途径。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。

项目成果

Unraveling Molecular Design Principle of Ferroelasticity in Organic Semiconductor Crystals with Two-Dimensional Brickwork Packing

• DOI: 10.1021/acs.chemmater.2c02534
• 发表时间: 2022-12
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Sang Kyu Park;Hongtao Sun;M. Bernhardt;Kyoungtae Hwang;J. Anthony;K. Zhao;Ying Diao

Molecular Mechanisms of Superelasticity and Ferroelasticity in Organic Semiconductor Crystals

有机半导体晶体超弹性和铁弹性的分子机制

• DOI: 10.1021/acs.chemmater.1c00080
• 发表时间: 2021
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Sun, Hong;Park, Sang Kyu;Diao, Ying;Kvam, Eric P.;Zhao, Kejie
• 通讯作者: Zhao, Kejie