Model-Based Ultrafast High Resolution Nano-Interrogation

纳米技术有可能通过对科学和技术的根本贡献来彻底改变人类的状况。实现纳米技术全部潜力的机会得到了最近在原子水平上对物质的合理控制和操纵的演示的支持。然而，尽管纳米技术在初创阶段取得了令人瞩目的成就，但在制造方法、系统设计和基本理解方面仍有艰巨的挑战需要克服。在这一新范式的承诺成为现实之前，这些挑战必须被克服。该提议的目标是建立一种在原子力显微镜(AFM)中实时使用模型的范式。实时使用模型的概念具有巨大的潜力，但尚未得到原子力显微镜工作者应有的重视，因为相关工具主要由工程师使用。这种透视有助于数据的解释，因为它提供了一种精确的方法，可以根据被探测样品的性质来描绘系统的内在动力学的影响。从而为解释样品性质提供了一种有效的手段。除了为新范式奠定基础的提议目标之外，该提议的具体目标还将导致一种新的原子力显微镜超快调查工具，称为瞬变力探测器(TFD)。该原型将在不影响样本大小和分辨率的情况下，每秒产生数十万个特征和检测率。TFD的一个特别优点是，取决于悬臂探头的品质因数的检测过程的分辨率与检测过程的速度是分离的。将解决探头信号损失和基于探头检测到样本的可能性的高分辨率成像的问题。实时使用模型非常适合探索基于模型的成像，在这种成像中，与检测相比，需要更详细的信息。只有当悬臂-样品相互作用模型可用于实时使用时，才能对样品进行更精细的表征。基于平均理论，提出了一种在纳米尺度上提取样本特征的方法，其中包括一种并行操作，即由建立在尖端-样本动力学平均分析结果基础上的实时模型来收集样本特征。提出了一种基于观测器理论的悬臂式测头主动修正方法。这一系统观点为调整针尖和样品的带宽、分辨率和作用力开辟了新的前景。这种增强的灵活性在目前的一套修改悬臂动力学的工具中是不存在的。将在拟议的调查中开发的创新方法将得到现有和未来的实验设施的补充。初步的概念验证结果表明，基于模型的成像范例具有巨大的潜力。广泛的影响：微型悬臂正被用于不同的领域，影响越来越大，并以一种根本性的方式影响着科学。所提出的方法是使能技术，并将通过提供超高带宽和分辨率来打开研究基础科学问题的大门。这些提案的创新贡献将直接影响扫描探针显微镜的大多数方面，因为所提出的方法适用于大多数现有的设备。例如，它将直接影响极高密度的数据存储(3TB/in2)和读出技术以及生物行业所采用的阵列技术。拟议研究的实验方面将与Asylum Research和Bioforce Nanosciences Inc.合作完成，这两家公司都是领先的生物相关扫描探针显微镜(SPM)公司。这一合作有望促进在该项目中开发的理论和技术在PI的学术机构和SPM行业之间的转移。PI已经成功地将系统和控制理论的观点传播给了大量参与扫描探针显微镜的物理界。根据这项提议的目标，和平协会将通过交换学生访问和举办专门的讲习班，继续推动两个社区之间专业知识的协同转让。和平协会正在与庇护研究合作，探索一种基于网络的SPM远程操作，可用于远程操作，这将有助于这一努力。

Nanotechnology has the potential to revolutionize the human condition through fundamental contributionsto science and technology. The chances of realizing the full potential of nanotechnology have been buttressedby recent demonstrations of rational control and manipulation of matter at the atomic level. Yet, in spite ofthe remarkable feats achieved in its nascent years, nanotechnology has formidable challenges to overcome inthe areas of manufacturing methods, system design, and basic understanding. These challenges have to beovercome before the promise of this new paradigm becomes a reality.The goal of this proposal is to establish a paradigm for real-time use of models in Atomic Force Microscopy(AFM). The concept of using models in real-time has significant potential that has not received the deservedattention by atomic force microscopists as the related tools are primarily employed by engineers. Such aperspective facilitates interpretation of data since it provides a precise means of delineating the effects ofthe inherent dynamics of the system from the properties of the sample being probed. Thus it provides aneffective means of interpreting sample properties. In addition to the proposal goal of laying the foundationsof a new paradigm, specific aims of the proposal will result in a new ultrafast investigation tool for AFM,termed the Transient Force Detector (TFD). The prototype will yield hundred thousand features per seconddetection rates without compromising sample size and resolution. A particular advantage of the TFD is thatthe resolution of the detection process, dependent on the quality factor of the cantilever probe, is decoupledfrom the speed of the detection process. Issues of the loss of the probe signal and high resolution imagingbased on the likelihood that the probe is detecting the sample will be addressed. Use of models in realtimeis very well suited to explore model based imaging where a more detailed information is desired whencompared to detection. A finer characterization of the sample will result only if cantilever-sample interactionmodels amenable for real-time use are available. Based on averaging theory, a methodology is proposed toextract sample characteristics that include topography, local stiffness and local damping at the nanoscale.This includes a parallel operation where the sample characteristics will be gleaned by real-time models builton the results of the averaging analysis of the tip-sample dynamics. Observer theory based active modificationof the cantilever probe is presented. This systems viewpoint opens up new vistas for tailoring bandwidth,resolution and forces on the tip and sample. This enhanced flexibility is absent from the present set of toolson modifying the cantilever dynamics. The innovative methods to be developed in the proposed investigationwill be complemented by the existing and future experimental facilities. Preliminary proof of concept resultsindicate the vast potential of the model based imaging paradigm presented.Broader Impacts: Micro-cantilevers are being used in diverse areas with increasing impact and has in-fluenced science in a fundamental manner. The methods proposed are enabling technologies and will opendoors for investigating basic science issues by providing ultra-high bandwidth and resolution. The innovativecontributions of the proposals will directly impact most aspects of scanning probe microscopy, as the proposedmethods apply to most of the existing setups. For example, it will directly impact the extremely highdensity data storage (3 Tb/in2) and read out technologies as well as the array technologies employed by thebio industry. The experimental aspects of the proposed research will be accomplished in collaboration withAsylum Research, and Bioforce Nanosciences Inc. both leading biology related scanning probe microscope(SPM) company. This collaboration is expected to foster transfer of the theory and technology developedin this program between the academic institution of the PI and the SPM industry. The PI has successfullydisseminated the system and control theory viewpoints to the physics community that is heavily involved inscanning probe microscopy. Under this proposal goals the PI will continue to push the synergistic transfer ofknowhow between the two communities by exchanging student visits and presenting specialized workshops.A web based remote operation of SPMs is being explored by the PI in collaboration with Asylum Researchthat can be used for remote operation that will aid this effort.