CDS&E: Scanning Electrochemical Microscopy with Compressed Sensing: Beyond the Point Probe

该项目由化学部的化学测量和成像计划资助。哥伦比亚大学的丹尼尔埃斯波西托和约翰赖特教授正在开发新的方法来扫描电化学显微镜（SECM），这将使大面积的高分辨率化学成像成为可能。SECM是一种扫描探针显微镜（SPM）技术，对于研究化学，物理和生物科学中的化学过程具有非常重要的价值。尽管SECM取得了成功，但它并不适合大面积的高分辨率成像。这种限制是因为传统的电化学探针以顺序的、逐点的方式扫描感兴趣的区域，这意味着在大面积上的高分辨率成像需要非常长的时间才能完成。目前的项目旨在打破这些权衡，并通过使用新的传感策略和先进的信号重建方法的组合，实现大样本的高效，高分辨率成像。这种方法将大大减少成像时间，从而扩展SECM在许多应用中的实用性。研究计划与教育和推广活动紧密结合。SECM已成为许多研究领域的宝贵工具。然而，SECM的一个主要缺点，共享许多SPM技术，是空间分辨率和区域扫描速率之间的权衡。SECM成像通常以纳米级分辨率执行，但这种高分辨率成像通常限于非常小的区域（通常为平方毫米）。传统SECM的慢面积扫描速率产生的事实，即扫描？点探针？，或超微电极，必须以顺序的、一次一个的方式扫描感兴趣区域内的每个（X，Y）位置。该项目旨在开发一种新的SECM成像方法，该方法结合了i.）非局部连续线探针（CLP）和ii.）先进的压缩传感（CS）信号分析技术。虽然CLP的几何结构使SECM信号能够在大面积上快速测量，但CS在从CLP生成的卷积SECM信号构建图像方面发挥着关键作用。该项目围绕三个主要目标组织：i.）展示CLP-SECM与CS相结合的核心优势，ii.）建立这种新方法的理论和实践限制，以及iii.）在宏观区域上实现具有纳米级分辨率的化学成像。研究和教育紧密结合在这个跨学科的研究项目中，重点是针对纳米技术和信号处理/数据分析新兴行业的教育活动和劳动力培训。

This project is funded by the Chemical Measurement and Imaging program of the Chemistry Division. Professors Daniel Esposito and John Wright of Columbia University are developing new approaches to scanning electrochemical microscopy (SECM) that will enable high resolution chemical imaging over large areas. SECM is a scanning probe microscopy (SPM) technique that has become invaluable for studying chemical processes across the chemical, physical, and biological sciences. Despite the success of SECM, it is not well suited for high resolution imaging over large areas. This limitation arises because conventional electrochemical probes are scanned in a sequential, point-by-point manner across the area of interest, meaning that high resolution imaging over large areas takes prohibitively long times to complete. The current project aims to break these tradeoffs and enable efficient, high-resolution imaging of large samples by using a combination of new sensing strategies and advanced signal reconstruction methodologies. This approach will greatly reduce imaging times and thereby expand the utility of SECM for many applications. The research plans are tightly integrated with educational and outreach activities.SECM has become an invaluable tool in many fields of study. However, a major shortcoming of SECM, shared by many SPM techniques, is the trade-off between spatial resolution and areal scan rates. SECM imaging is commonly performed with nanoscale resolution, but such high resolution imaging is typically limited to very small areas (typically square millimeters). The slow areal scan rates of conventional SECM arise from the fact that the scanning ?point probes?, or ultramicroelectrodes, must be scanned across every (X,Y) location within in an area of interest in a sequential, one-at-a-time manner. This project aims to develop a new approach to SECM imaging that combines i.) non-local continuous line probes (CLPs) and ii.) advanced compressed sensing (CS) signal analysis techniques. While the CLP geometry enables SECM signal to be rapidly measured over large areas, CS serves the critical role of constructing images from the convoluted SECM signal generated by the CLP. The project is organized around three primary objectives: i.) demonstrating the core benefits of combining CLP-SECM with CS, ii.) establishing the theoretical and practical limits of this new approach, and iii.) achieving chemical imaging with nanoscale resolution over macroscopic areas. Research and education are tightly integrated within this interdisciplinary research project, with a strong emphasis on educational activities and workforce training that targets the emerging industries in nanotechnology and signal processing / data analytics.