Experimental and Numerical Studies of Cantilever Sensors

现有的检测淡水中重金属的方法需要收集样品并送到专门的实验室进行分析。 这样的程序是耗时且昂贵的。 便携式设备包含阵列的微悬臂梁传感器能够检测几种分析物在同一时间，有一天，可以用于执行一个完整的重金属分析的水现场，快速，成本效益，并与最少的用户培训。 微悬臂梁传感器是大约400微米长、50微米宽和1微米厚的小悬臂梁，被功能化以接受特定的目标分析物。 由于其体积小，数百个杠杆可以合并在一个一角硬币大小的区域。 尽管悬臂梁传感器提供了满足上述目标的所有必要标准，但其可重复性阻止了它们被实施到商业设备中。本申请的主要目的是研究，使用实验观察和数值建模和模拟的创新组合，影响悬臂梁传感器的再现性的因素，通过：探索材料科学问题，如用于锚感测层的薄Au膜的形态;使用流体动力学模拟理解分析物如何在传感器单元内流动;以及研究设计用于检测特定重金属的新型杯芳烃传感层的主体/客体反应。 拟议工作的结果将加快悬臂梁传感器在商业设备中的应用，用于从检测病毒到爆炸装置中的痕量气体的各种应用。 了解材料科学问题将有利于各种传感器技术，将化学或生物刺激转化为机械响应。 开发用于测量淡水中重金属含量的便携式设备的长期目标不仅将使加拿大受益，而且将使世界各地的政府和环境保护机构受益，因为我们的淡水资源污染持续增长。 作为第二个目标，这将依赖于我的专业知识，在扫描探针显微镜，我们将努力成为第一个调查的有效性新理论的摩擦和摩擦老化。 摩擦和摩擦老化是材料的基本性质，从机器磨损到构造板块的运动都有深远的影响。 了解这些基本概念最终会带来控制它们的能力，这可能对从开发更高效的发动机到更耐磨的工具等许多技术应用产生重大影响。 我们还将尝试开发一种新的理论，以更好地解释动态力谱测量。 如果成功的话，这项工作的结果将允许以前所未有的准确度测量分子和生物键的强度。

Existing methods for detecting heavy metals in fresh water require samples be collected and sent to specialized laboratories to be analyzed. Such a procedure is time consuming and expensive. Portable devices containing arrays of microcantilever sensors capable of detecting several analytes at one time could, one day, be used for performing a complete heavy metal analysis of water onsite, quickly, cost effectively, and with minimal user training. Microcantilever sensors are small cantilevers approximately 400 microns long, 50 microns wide, and 1 micron thick functionalized to be receptive to specific target analyte. Because of their small size, hundreds of cantilevers can be incorporated in an area the size of a dime. Although cantilever sensors offer all the necessary criteria for satisfying the above goal, their reproducibility has prevented them from being implemented into commercial devices. The principle objective of this application is to investigate, using an innovative combination of experimental observations and numerical modeling and simulations, the factors that affect the reproducibility of cantilever sensors by: exploring the materials science issues such as the morphology of the thin Au film used to anchor the sensing layer; understanding how analyte flows within the sensor cell using fluid dynamics simulations; and studying the host/guest reactions of new calixarene sensing layers designed to detect specific heavy metals. The results of the proposed work will quicken the application of cantilever sensors into commercial devices for a variety of applications from detecting viruses to trace gases from explosive devices. Understanding the materials science issues will benefit a variety of sensor technologies that translate a chemical or biological stimulus into a mechanical response. The long term objective of developing portable devices for measuring heavy metal levels in fresh water will not only benefit Canada but also governments and environmental protection agencies worldwide as the contamination of our freshwater sources continues to grow. As a second objective, which will rely on my expertise in scanning probe microscopy, we will endeavour to be the first to investigate the validity of new theories of friction and frictional aging. Friction and frictional aging are fundamental properties of materials with far reaching implications from machine wear to the motion of tectonic plates. Understanding these fundamental concepts ultimately leads to the ability to control them which could have significant implications in many technological applications from developing more efficient engines to more wear resistant tools. We will also attempt to develop a new theory to better interpret dynamic force spectroscopy measurements. If successful the results of this work will allow the strength of molecular and biological bonds to be measured with unprecedented accuracy.