EAGER: Transforming Flexible Device Manufacturing by Bottom-up Growth of Nanocarbons Directly on Polymers

这个早期概念的探索性研究（EAGER）奖赠款的重点是揭示激光诱导纳米碳形成的基本原理，LINC，这是一种新的纳米制造工艺，能够快速增长的各种纳米结构的碳材料直接在聚合物上。这种方法能够实现功能性纳米碳的图案化，这些功能性纳米碳是医疗保健，生物医学，汽车，消费电子和国防等许多新兴应用所需的。该项目能够定制具有精确空间分布的纳米碳类型，从而在同一基板上快速创建不同器件的优化结构，而无需多种油墨和连续的印刷步骤。而不是自上而下的沉积或打印的纳米碳，如石墨烯和纳米管/纳米纤维从墨水，这项研究的重点是自下而上的热化学合成不同的纳米碳从聚合物，作为碳源下高度局部化的激光加热。该项目影响了数十亿美元的柔性电子市场，其中一个主要挑战是将传感，储能和电路等多种功能集成到同一柔性基板上。 LINC是制造适形/可穿戴和其他设备的一种简便、可扩展的途径，有利于美国经济。 EAGER项目的主要目标是展示基于聚合物动态激光加工的柔性基底上具有定制形态和特性的不同纳米碳的可扩展直接图案化的概念验证。激光诱导纳米碳（LINC）方法需要了解聚合物的热化学碳化的机制和动力学，以及用于传感和其他功能的生长纳米碳的电性能的可调谐性。因此，该项目通过阐明光能（激光）通量的时空演变和随后的光热加热对石墨碳含量的影响以及对形成各向同性多孔形态和对齐的非晶结构之间的过渡产生新的知识。因此，该项目构建了激光能量密度梯度与吸收，传热，飞溅动力学，相变和化学转化等温度依赖性多物理现象之间的因果关系，这些现象决定了石墨烯，碳纳米纤维和碳纳米管等不同纳米碳的形成。除了解释碳纳米丝之间的对齐和自组织机制外，该项目还直接在聚酰亚胺薄膜上测试基于kirigami的应变传感器的制造和性能。此外，通过将振镜系统的快速光纤激光扫描与卷对卷加工相结合的应变传感器的连续制造，测试了这种新方法的可扩展性。该奖项反映了NSF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。

This EArly-concept Grants for Exploratory Research (EAGER) award focuses on revealing the fundamental principles underlying laser-induced nanocarbon formation, LINC, which is a new nanomanufacturing process capable of rapidly growing a diverse set of nanostructured carbon materials directly on polymers. This approach enables patterning of functional nanocarbons that are needed for a number of emerging applications in healthcare, biomedical, automotive, consumer electronics, and defense. This project enables customization of the nanocarbon type with precise spatial distribution to rapidly create optimized structures for different devices on the same substrate without the need for multiple inks and successive printing steps. Instead of top-down deposition or printing of nanocarbons such as graphene and nanotubes/nanofibers from ink, this research focuses on bottom-up thermochemical synthesis of different nanocarbons from polymers, which act as the carbon source under highly localized laser heating. This project impacts a multibillion-dollar market for flexible electronics where a major challenge is the integration of multiple functionalities, such as sensing, energy storage and circuits onto the same flexible substrate. LINC is a facile, scalable pathway to manufacturing of conformal/wearable and other devices, which benefits US economy. The main goal of this EAGER project is to show a proof-of-concept for scalable direct patterning of different nanocarbons with tailored morphologies and properties on flexible substrates based on dynamic laser processing of polymers. The laser-induced nanocarbon (LINC) method requires an understanding of the mechanisms and kinetics of thermochemical carbonization of polymers and of the tunability of the electrical properties of grown nanocarbons for sensing and other functionalities. Hence, this project generates new knowledge by elucidating the influence of the spatiotemporal evolution of optical energy (laser) flux and the ensuing photothermal heating on the content of graphitic carbon as well as on the transition between forming isotropic porous morphology and aligned filamentary structures. As a result, this project constructs the causal relation between gradients of laser energy density and the temperature-dependent multiphysics phenomena of absorption, heat transfer, splashing dynamics, phase transitions and chemical transformations, which dictate the formation of different nanocarbons such as graphene, carbon nanofibers, and carbon nanotubes. In addition to explaining the mechanisms of alignment and self-organization among carbon nanofilaments, the project tests the fabrication and performance of kirigami-based strain sensors directly on polyimide films. Moreover, the scalability of this new approach is tested by continuous manufacturing of strain sensors based on combining fast fiber laser scanning using a galvo system with roll-to-roll processing.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.