CAREER: Self-organization and shape change in elastic active matter

职业：弹性活性物质的自组织和形状变化

• 批准号: 2340632
• 负责人: Kinjal Dasbiswas
• 金额: $ 63万
• 依托单位: University of California - Merced
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-05-15 至 2029-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340632&HistoricalAwards=false
• 关键词: CAREER; Self; organization; shape; change

NONTECHNICAL SUMMARYThis CAREER award supports theoretical and computational research to describe and understand the behavior of biologically inspired active solids. The models developed in this research are motivated by mechanical force-driven shape changes in living matter occurring in the cell cytoskeleton and multicellular tissues. Living matter utilizes chemically patterned mechanical forces to change shape in programmed and robust ways during crucial biological processes such as tissue development and cell migration. They are thus excellent examples of active matter which comprise microscopic components that consume energy to generate mechanical forces and motion. Unlike active fluids where constituent components move freely, biological materials typically contain connected networks of polymers that respond to mechanical force by deforming like elastic springs. Further, unlike ordinary solids that deform under externally applied forces to reach a well-defined minimal energy state, the force-generating units of active solids are embedded within the material itself and can be redistributed by the deformations that they themselves generate. These unique features enable active solids to autonomously generate patterns and shapes not found in ordinary solids under thermodynamic equilibrium. The PI and his research team will create theoretical and computational models of shape-changing active solids by combining mechanical and chemical factors. The general aim is to theoretically and computationally investigate the unique shape changes and self-organization phenomena that are possible in active solids. The results will be compared with experimental data on cytoskeletal materials and blood clots obtained from the PI’s collaborators. Our research will provide fundamental understanding of self-organization in cell biology and tissue morphogenesis. It may influence strategies in tissue engineering as well as the design of synthetic soft materials capable of autonomous shape change. Education and outreach activities are integrated with this research. These center on creating unique interdisciplinary learning opportunities involving computation for students at multiple levels. The PI will (1) deliver summer computational workshops to high school students; (2) develop computational modules for the introductory physics classes for life science majors as well as core physics classes; and (3) train beginning graduate students in scientific computing basics through a summer bridge module. These educational and outreach efforts will help recruit and train the future STEM workforce in the underserved San Joaquin Valley of California and beyond. TECHNICAL SUMMARYThis CAREER award supports the development of a physical theory of spontaneous shape change and self-organization in elastic active matter through biologically inspired mechano-chemical feedback. It also supports the PI’s educational initiative to train students at multiple levels in scientific computation through interdisciplinary biophysical models. Active matter refers to collections of entities that consume chemical energy and generate mechanical forces and motion. In contrast to active fluids that contain self-propelling particles, active solids comprise constituents connected via elastic spring-like constraints that exhibit deformations instead of large-scale flows in response to mechanical force. In living matter, these mechanical forces are generated by molecular motors whose activity is patterned by chemical signals. The research will be inspired by the inherently mechano-chemical nature of living matter occurring both in the cell cytoskeleton and in multicellular tissue. The PI and his research team will develop a class of models combining active mechanical forces, elastic deformation, orientational order and chemical gradients, and their mutual interactions, leading to spontaneous shape change and pattern formation. The team of the PI will focus on two nonlinear mechanical systems that respond sensitively to mechanical forces: thin elastic shells that undergo 3D shape changes by buckling because of their inherent geometric nonlinearity, and disordered fiber networks that exhibit complex nonlinear deformation modes. Complementary modeling strategies will be used, including continuum models amenable to theoretical analysis, as well as discrete network models for numeric computation. The research will reveal how elastic deformations of living matter contribute to 1) the regulation of chemical concentration by geometry and strain; 2) mutual elastic interactions between active units driving their self-organization dynamics into ordered states; 3) long-range orientational order and associated topological defects through deformation-induced alignment, and 4) complex 3D shapes arising through various buckling instabilities. The PI proposes an integrated educational plan involving computational training at multiple levels, from K-12 to undergraduate and graduate students. This will be delivered through 1) summer computational workshops and demonstrations designed for K-12 school students; 2) computational modules for the introductory physics classes for life science majors as well as core physics classes; and 3) training beginning graduate students through a summer bridge program on computational skills. These educational and outreach activities will contribute to the recruitment, retention, and training of students in STEM fields in the underserved San Joaquin Valley region of California. The research will provide training for a graduate student and a postdoc, and impact several fields including active matter physics, cell biology and tissue engineering, as well as bio-inspired soft materials 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.

非技术摘要这一职业奖支持理论和计算研究，以描述和理解生物学启发的活跃固体的行为。在这项研究中开发的模型是由细胞骨骼和多细胞组织中的生物发生的机械驱动形状变化所激发的。生命物质利用化学图案的机械力在关键的生物学过程（例如组织发育和细胞迁移）中以编程和可靠的方式改变形状。因此，它们是活性物质的极好例子，其中包括耗尽能量来产生机械力和运动的微观组件。与活性流体自由移动的活性流体不同，生物学材料通常包含连接的聚合物网络，这些网络通过像弹性弹簧那样变形来响应机械力。此外，与普通固体在外部施加力下变形以达到明确定义的最小能状态不同，活性固体的力产生单位嵌入材料本身中，并且可以被其本身产生的变形重新分布。这些独特的特征使活跃的固体能够自主产生在热力学平衡下在普通固体中找不到的图案和形状。 PI和他的研究团队将通过结合机械和化学因子来创建理论和计算模型的变化活性固体。总体目的是理论和计算研究主动固体中可能的独特形状变化和自组织现象。结果将与从PI合作者获得的细胞骨架材料和血凝块的实验数据进行比较。我们的研究将提供对细胞生物学和组织形态发生中自组织的基本理解。它可能会影响组织工程的策略以及能够自主形状变化的合成软材料的设计。教育和外展活动与这项研究融合在一起。这些以创造独特的跨学科学习机会的重点涉及多个级别的学生的计算。 PI将（1）向高中生提供夏季计算工作； （2）为生命科学专业的物理类别以及核心物理课程开发计算模块； （3）通过夏季桥梁模块在科学计算基础知识中训练初学者。这些教育和宣传工作将有助于在加利福尼亚州及其他地区及其服务不足的圣华金山谷中招募和培训未来的STEM劳动力。技术摘要这一职业奖支持通过生物学启发的机械化学反馈来发展弹性主动物质中赞助商形状变化和自组织的物理理论的发展。它还支持PI的教育计划，以通过跨学科的生物物理模型在科学计算中培训学生。主动物质是指消耗化学能并产生机械力和运动的实体的集合。与含有自然销售颗粒的活性流体相反，活性固体构成通过弹性弹簧样约束连接的，这些弹性弹性的约束因响应机械力而导致变形而不是大规模流动。在生物物质中，这些机械力是由分子电动机产生的，其活性是由化学信号模式化的。这项研究将受到在细胞骨骼和多细胞组织中固有机械性质的固有机械性质的启发。 PI和他的研究团队将开发一类模型，结合了主动的机械力，弹性变形，定向顺序和化学梯度及其相互作用，从而导致自发形状变化和模式形成。 PI团队将集中在两个非线性机械系统上，它们对机械力敏感：由于其继承的几何非线性而导致3D形状变化的薄弹性壳以及暴露了复杂非线性变形模式的无序纤维网络。将使用互补的建模策略，包括适合理论分析的连续模型，以及用于数字计算的离散网络模型。该研究将揭示生物的弹性变形如何促进1）通过几何和应变来调节化学浓度； 2）主动单元之间的相互弹性相互作用将其自组织动态推向有序状态； 3）通过变形诱导的对齐方式和4）复杂的3D形状通过各种屈曲不稳定性产生的复合体3D形状。 PI提案提出了一项综合教育计划，涉及从K-12到本科和研究生的多个级别的计算培训。这将通过1）为K-12学校学生设计的夏季计算工作和演示； 2）生命科学专业的物理课程以及核心物理课程的物理课程的计算模块； 3）通过夏季桥梁计划培训学科的培训研究生。教育和外展活动将有助于加利福尼亚州圣华金河谷地区的STEM领域的学生的招募，保留和培训。这项研究将为研究生和博士后提供培训，并影响多个领域，包括活跃物理，细胞生物学和组织工程以及受到生物启发的软材料设计。这项奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和广泛影响的评估来通过评估来获得支持的。