CAREER: Optical Super-Resolution Nanothermometry via Stimulated Emission Depletion Imaging

我们生活在一个纳米技术的时代，无处不在的设备，如为我们的通信提供动力的笔记本电脑和智能手机，存储数据的硬盘驱动器，以及照亮我们建筑物的发光二极管，都包含了大量的纳米级组件。这些电子、数据存储和能量转换设备也必须在极端温度、高压、大电磁场和恶劣化学环境等具有挑战性的条件下运行。同时，热性能在决定这些技术的整体性能方面发挥着巨大的作用。例如，散热不良会限制电子产品和硬盘驱动器的可靠性，而高性能隔热材料必须大大减少热量传递。因此，具有纳米尺度空间分辨率的非侵入性温度测绘对于优化各种现代技术的性能和可靠性至关重要。然而，大多数现有的测温技术要么需要用温度探头与样品进行物理接触，这可能会干扰样品并妨碍在具有挑战性的环境中进行测量，要么缺乏解决纳米尺度温度非均质性所需的空间分辨率。本提案的中心目标是通过开发一种新的超分辨率纳米测温技术来解决这些挑战，从而实现亚衍射有限空间分辨率的远场光学温度映射。所提出的技术依赖于被称为上转换纳米粒子的发光纳米材料，它可以在广泛的条件下工作，并且与样品形状因素或材料类型无关。使用定制的成像和光谱系统，首席研究员和她的研究小组将采用诺贝尔奖获奖的超分辨率成像技术，称为受激辐射损耗，用于测温。该团队将演示温度依赖的受激发射耗尽光谱，使用空间分辨受激发射耗尽测量来绘制微制造加热器结构的表面温度分布图，空间分辨率低至~60 nm，并应用受激发射耗尽纳米热测量来揭示操作光电器件的失效机制，这是现有技术无法完全解决的主要挑战。与此同时，综合教育计划将通过创建一个开源硬件存储库，使热显微镜大众化，并通过小学外展伙伴关系，帮助确保下一代未被充分代表的群体充分参与科学和工程领域。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。

We live in an era of nanotechnology, where omnipresent devices like the laptops and smart phones that power our communications, the hard drives that store our data, and the light-emitting diodes that illuminate our buildings contain a multitude of nanoscale components. Increasingly, these electronic, data storage, and energy conversion devices must also operate under challenging conditions, including extreme temperatures, high pressures, large electromagnetic fields, and harsh chemical environments. Simultaneously, thermal properties play an outsize role in determining the overall performance of these technologies. For example, poor heat dissipation can limit the reliability of electronics and hard drives, while high-performance thermal insulation materials instead must greatly reduce heat transfer. Non-invasive temperature mapping with nanoscale spatial resolution is thus critical for optimizing the performance and reliability of a wide array of modern technologies. However, most existing thermometry techniques either require physically contacting samples with a temperature probe, which can perturb the sample and preclude measurements in challenging environments, or else lack the spatial resolution needed to resolve nanoscale temperature heterogeneities. The central goal of this proposal is to address these challenges by developing a novel super-resolution nanothermometry technique, enabling far-field optical temperature mapping with sub-diffraction limited spatial resolution. The proposed technique relies on luminescent nanomaterials called upconverting nanoparticles that can operate under wide-ranging conditions and independent of sample form factor or material type. Using a custom-built imaging and spectroscopy system, the principal investigator and her research team will adapt a Nobel Prize-winning super-resolution imaging technique called stimulated emission depletion for thermometry. The team will demonstrate temperature-dependent stimulated emission depletion spectroscopy, use spatially resolved stimulated emission depletion measurements to map surface temperature profiles of microfabricated heater structures with spatial resolution down to ~60 nm, and apply stimulated emission depletion nanothermometry to uncover failure mechanisms in operating optoelectronic devices, a major challenge that cannot be fully addressed by existing techniques. In concert, the integrated education plan will democratize thermal microscopy via the creation of an open source hardware repository and help ensure full participation of the next generation of underrepresented groups in science and engineering fields through an elementary school outreach partnership.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.