Laser-Based Processing of Graphene Aerogels in the Manufacture of Ultra-performance Bolometers

该项目为激光制造提供了新的知识，可用于将新型超低密度功能材料整合到有用的器件结构中。辐射热计在民用和军事领域都有非常广泛的应用，包括热成像，夜视，天文学，安全和粒子物理。为了实现高灵敏度和快速响应，热计系统需要非常有效的光吸收，其电阻的高温响应，对环境的热损失非常低，热电容非常小。现有的热辐射计缺乏宽光谱响应，性能需要显著提高以满足各种需求。该项目开发了一种新的制造工艺，使用激光控制的化学反应来制造非常高灵敏度的辐射热计，该辐射热计具有快速的响应时间和对紫外线到远红外辐射的优异灵敏度。激光控制的化学反应用于制造和定制石墨烯气凝胶，以制造亚微米尺寸的测热计。该项目利用激光制造的空间精度来研究图案、化学和电气材料的改性。这项工作取得的进展将有利于美国经济和潜在的国家安全应用，并有可能影响其他气凝胶材料的制造。这项研究将涉及广泛的研究生和本科生培训以及对K-12年级学生的教育推广。由于其优异的光子吸收性能和多孔结构，石墨烯气凝胶具有非常高（接近100%）和宽带的光子吸收（紫外到毫米）。目前的石墨烯气凝胶制造工艺不能直接用于微米尺度的测热计，激光制造具有提供高空间分辨率的材料改性和优化控制材料性能变化的额外潜力。为了满足设备需求，该项目旨在开发一种激光控制的化学还原技术，允许直接制造亚微米尺度的石墨烯气凝胶热计。研究团队将开发激光控制的化学还原和n掺杂，用于直接制造高度确定尺寸（小到亚微米）的石墨烯气凝胶热计，并直接可扩展地集成到微尺度电路中。研究激光参数的影响，揭示制备条件与石墨烯气凝胶结构和性能之间的关系。通过调整石墨烯气凝胶的表面官能团，研究团队将显著优化GA测热计的灵敏度。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。

This project contributes new knowledge related to laser-based manufacturing which can be used to incorporate novel ultra-low-density functional materials into useful device structures. Bolometers have very broad applications in both civilian and military fields including thermal imaging, night vision, astronomy, security, and particle physics. To achieve high sensitivity and fast response, the bolometer system requires very efficient light absorption, high temperature response of its electrical resistance, very low heat loss to the environment, and very small heat capacitance. Existing bolometers lack wide spectrum response and the performance needs to be improved significantly to meet various needs. This project develops a novel manufacturing process using laser-controlled chemical reactions to make very high sensitivity bolometers that have a fast response time and excellent sensitivity to radiation from ultraviolet to far-infrared. The laser-controlled chemical reaction is used to manufacture and tailor graphene aerogels to make sub-micron size bolometers. The project investigates the patterning and chemical, and electrical materials modification using spatial precision available through laser-based manufacturing. The advances made in this work will benefit the U.S. economy and potential national security applications, with the potential to impact the manufacture of other aerogel materials. This research will involve extensive graduate and undergraduate student training and education outreach to K-12 graders.Because of its excellent photon absorption properties and porous structure, graphene aerogel has both a very high (close to 100%) and wideband photon absorption (ultraviolet to millimeter). Current graphene aerogel manufacturing processes cannot be directly used for making micron-scale bolometers Laser-based manufacturing has the additional potential to provide materials modification with high spatial resolution and optimized control over the changes in materials properties. Addressing the device need, this project is designed to develop a laser-controlled chemical reduction technique allowing for the direct manufacturing of graphene aerogel-based bolometers down to sub-micron scale. The research team will develop laser-controlled chemical reduction and N-doping for direct manufacturing of graphene aerogel bolometers of highly defined size (down to sub-µm) with direct and scalable integration to microscale circuits. The effect of laser parameters will be investigated to uncover the relations between manufacturing conditions and graphene aerogel structure and properties. Via tailoring the surface functional groups within the graphene aerogel, the research team will significantly optimize the sensitivity of GA bolometers.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.