The Ultimate Strength of Carbon Nanotubes

1 9711785 Smalley这个选定的研究机会补助金的目的是询问单个单壁碳纳米管（SWNT）的真实拉伸强度。 实现这些非常困难的实验将需要在隔离，操纵和固定单壁碳纳米管绳到制造的支持技术的重大改进。 单壁碳纳米管的一个连续的绳索将被覆盖在斯坦福大学纳米工厂制造的硅晶片上的金属线特征上。 然后将样品引入原子力显微镜中，该原子力显微镜将用于三个目的：（1）将周期性地扫描整个样品，首先寻找有吸引力的跨度，随后寻找断裂和滑动的迹象;（2）对位于跨度两侧的支撑线上的绳索的高分辨率扫描将产生绳索的几何形状，给出了绳索中SWNT数量的良好估计;（3）AFM尖端将在跨度中间的一个点处接合以使绳索偏转。 已知的AFM悬臂力常数沿着与测量的偏转将提供所需的信息，以获得绳索和各个管的拉伸强度。 %%% 新 有证据表明，碳纳米管是 已知最强的材料， 在对美国经济至关重要的许多领域的独特应用。 这项研究将涉及使用显微操作器直接测量纳米管绳的强度。 结果将为研究提供基础 纳米管基超强材料及其应用

1 9711785 Smalley The objective of this Selected Research Opportunity Grant is to interrogate the true tensile strength of an individual single-wall carbon nanotube (SWNT). Achieving these very difficult experiments will require substantial improvements in techniques for isolating, manipulating, and securing SWNT ropes onto fabricated supports. A single continuous rope of SWNTs will be draped cross metallic line features on a silicon wafer fabricated at the Stanford Nanofabrication Facility. The sample will then be introduced into an atomic force microscope which will be used for three purposes: (1) The entire sample will be scanned periodically, first to find an attractive span, and subsequently to look for signs of breakage and slippage; (2) High-resolution scans of the rope lying on the support lines on either side of the span will yield the geometry of the rope, giving a good estimate for the number of SWNTs in the rope; (3) The AFM tip will be engaged at one point in the middle of the span to deflect the rope. The known AFM cantilever force constant along with the measured deflections will provide the information required to obtain tensile strengths of the rope and of the individual tubes. %%% New evidence suggests that carbon nanotubes are the strongest materials known, potentially enabling unique applications in many areas critical to the U.S. economy. This research will involve direct measurements of the strength of nanotube ropes using micromanipulators. The results will provide the foundation for research and development of nanotube based superstrong materials and their applications