查看完整版本: Nano-Sun: From Traditional Printing to High Resolution Nano-Printing

Nano-Sun: From Traditional Printing to High Resolution Nano-Printing

[size=5][b]Nano-Sun: From Traditional Printing to High Resolution Nano-Printing[/b][/size]

[b]【纳米科技世界快讯】IBM researchers in collaboration with scientists from the ETH Zurich have demonstrated a new, efficient and precise technique to “print” at the nanoscale.[/b]

[i][attach]1772[/attach]
This image created by IBM scientists demonstrates a new nano "printing" technique they believe will lead to breakthroughs in ultra-tiny chips, optics, and biosensors. The recreation of Robert Fludd's 17th century drawing of the Sun – the alchemists’ symbol for gold -- was created by precisely placing 20,000 gold particles, each about 60 nanometers in diameter. This method could be used for mass production to place particles as small as 2 nanometers in diameter to fabricate atomic scale nanowires, ultra tiny lenses for optics and biosensors for healthcare. Credit: IBM[/i]

The method, which allows the scientists to place individual particles precisely where they want them, could advance the development of nanoscale biosensors, ultra-tiny lenses that can bend light inside future optical chips, and the fabrication of nanowires that might be the basis of tomorrow’s computer chips.

Though still a few years from being used widely, the new technique shows promise for real world applications outside of the lab without major profound new inventions, and could lead to high-volume manufacturing techniques for nanostructures inside chips and other devices that are more efficient and cost less than today’s methods.

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[i]Top - The traditional printing method known as "gravure printing", where an image is etched on the surface of a metal plate, the etched area is filled with ink, then the plate is rotated on a cylinder that transfers the image to paper or other material. This method allows for features as small as 10,000 nanometers, far too big for use in electronics. Bottom - IBM's novel new nano printing method, which uses a self-assembly process to control the arrangement of tiny nanoparticles, in this case 20,000 gold particles, each about 60 nanometers in diameter. The gold nanoparticles are swept across a surface and convective forces in the liquid push the particles into grooves in the surface, forming nanostructures with a well-defined geometry. The IBM scientists believe this method could be used for mass production -- more efficiently and at a lower cost -- to place particles as small as 2 nanometers in diameter to fabricate atomic scale nanowires, ultra tiny lenses for optics and biosensors for healthcare. Credit: IBM[/i]

“This method opens up new ways to precisely and efficiently position various kinds of nanoparticles on different surfaces, a prerequisite for exploiting the unique properties of such nanoparticles and for making their use economically feasible,” explains Heiko Wolf, researcher in nanopatterning at IBM’s Zurich Research lab.

The achievement, published in the September issue of the journal Nature Nanotechnology, offers a promising and powerful new tool for use in a wide range of fields and industries such as biomedicine, electronics and IT that seek ways to exploit the often unique properties of so-called nanoparticles, which are defined as particles smaller than 100 nanometers.

Until now, standard top-down micro-fabrication techniques produce such tiny particles by in effect carving them out of a bigger piece of material. Printing, in contrast, adds ready-made nanoparticles onto a surface in a very efficient way and allows for different types of materials such as metals, polymers, semiconductors, and oxides to be combined in one process.

For the first time, the researchers printed particles as tiny as 60 nanometers -- roughly 100 times smaller than a human red blood cell -- with single-particle resolution to create nano-patterns ranging from simple lines to complex arrangements. Translating the resolution of these particles into a traditional printing term known as “dots per inch” or dpi, a standard measure that defines how many individual spots of ink can be printed on a certain area, the nanoprinting method yields 100,000 dots per inch, whereas common offset printing today operates at 1,500 dpi.

To demonstrate the efficiency and the versatility of their method, the researchers chose to print Robert Fludd’s 17th-century image of the sun, the alchemists’ symbol for gold. Quite fittingly, it is printed out of roughly 20,000 gold particles, each of them 60 nanometers in diameter. The printing method precisely placed one particle per dot, thus creating the smallest piece of artwork ever printed from single pigment particles.

[b]Nanoprinting Applications[/b]

In biomedicine this printing process could, for example, be applied to the printing of large arrays of biofunctional beads that can detect and identify certain cells or markers in the body. One example could be rapid screening for cancer cells or heart attack markers. As part of new point-of-care diagnostic devices, regular arrays of functional beads could enable a fast and automated read-out that only needs the tiniest amounts of samples.

Nanoparticles can also interact with light. With the new method, optical materials with new properties could be printed, for example, for use in optoelectronic devices. So-called “metamaterials” could be created in which the printed structures are as small as the wavelength of the light and therefore act as if they were a single lens with unusual properties.

Moreover, the method holds promise for semiconductors. In one experiment, the researchers achieved the controlled placement of catalytic seed particles for growing semiconducting nanowires. Such nanowires are promising candidates for future transistors in microchips.

[b]Printing on the Nanoscale[/b]

“In traditional gravure printing, a doctor blade is used to fill the recessed features of a printing plate with ink, in which pigment particles are randomly dispersed,” explains Tobias Kraus, of the nanopatterning team in Zurich. “In our high-resolution printing, a directed self-assembly process controls the arrangement of nanoparticles on the printing plate or template. The entire assembly is then printed onto a target surface, whereby the particle positions are precisely retained at a resolution that is three orders of magnitude higher than in conventional printing.”

The printing template geometries explored include lines to produce closely-packed nanoparticle wires, which could be used in molecular electronics; regularly spaced arrays of gold particles as seeds for nanowire growth; and arbitrary arrangements, such as the printed replica of the sun. The long-range accuracy, which measures the deviation from the desired arrangement on a large area, is similar to that of microcontact printing methods. The next steps will be to refine the method to achieve even higher accuracies, as would be required for large-scale integration in microelectronics, as well as to extend the method to print even smaller particles.

Source: IBM

我来补充这篇论文的下载,
[url]http://rapidshare.com/files/55060303/nnano.2007.262Nanoparticle_printing_with_single-particle_resolution.pdf[/url]

回复 #2 bankkom 的帖子

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[[i] 本帖最后由 bankkom 于 2007-09-12 11:36 编辑 [/i]]

[i]图注：IBM科学家开发出一种新的纳米“打印”技术，他们相信该技术将促使超微苾片、光学和生物传感器领域取得突破。作为示范，IBM打印了一张罗伯特·弗鲁德在17世纪创作的太阳图（炼金术士的黄金图腾），图片中精确地放置了2万颗黄金粒子，每颗直径约为60纳米。这种打印方法可以用于放置直径为两纳米的粒子以大规模制造原子级的纳米线、超微型光学镜头和医疗用生物传感器。（图片来源：IBM）[/i]

　　IBM研究员与苏黎世瑞士联邦理工大学科学家共同示范了一种精确高效的新型纳米级“印刷”技术。这种打印方法允许科学家按照他们的意图精确地放置单个粒子，它将推动纳米级生物传感器和超微型光学镜头（这种镜头可以使光在未来的光学芯片内部发生弯曲）的发展以及纳米线（未来计算机芯片的基础）的制造。

　　这项新技术不需要依赖重大新发明，有望在实验室以外的现实世界中得到运用，尽管它距离广泛应用还有几年的时间。它将导致芯片和其它设备内部的高容量纳米结构制造技术的产生。与今天的方法相比，这种技术不仅更加有效，而且成本低廉。

　　传统的印刷技术，即照相凹版印刷技术，是把图像蚀刻在金属板的表面，再在蚀刻区填满墨水，然后把金属板卷在一个圆柱体上，通过圆柱体的旋转使图像印在纸或其它材料上。这种方法只能印刷一万纳米以上的墨点，由于墨点过大，无法用于印制电子器件。IBM的创新型纳米打印技术运用了自装配过程，可以控制微纳米粒子的排列。在这张图片中，共排列了20000个金色粒子，每个直径60纳米。科学家让黄金纳米粒子扫过材料的表面，液体内的对流张力把黄金纳米粒子压入了材料表面里的凹缝中，从而形成了具有明确几何形态的纳米结构。IBM科学家相信这种方法可以放置直径为2纳米的粒子以制造原子级的纳米线、超微型光学镜头和医疗用生物传感器，从而实现低本高效的大规模生产。

    IBM苏黎士实验室纳米图案研究员海科·沃尔夫解释称：“这种方法开辟出了新的途径，可以精确和有效地在不同的表面上放置不同类型的纳米粒子，这也是利用纳米粒子独特属性和实现经济可行性的先决条件。”

   这项成果已经发表在9月份的《自然-纳米科技》杂志上，它提供了一种有前途的和强大的新工具，可以广泛用于不同的行业和领域，比如生物医学、电子学和IT业，而这些行业和领域正在寻求有效利用纳米粒子(100纳米以下的粒子被定义为纳米粒子)独特属性的途径。

   迄今为止，标准和严密的微制造技术是通过有效地雕刻微材料来制造纳米粒子。而打印技术是把现成的纳米粒子以非常有效的方式印制在材料表面上，允许一次性打印不同的材料，比如金属、聚合体、半导体和氧化物。

  首先，科研人员用60纳米的粒子（比人的红细胞小100倍）来打印纳米图案，这些图案包括简单的线条甚至复杂的排列，其分辨率达到了单一粒子的程度。如果用传统的“每英寸点数（dpi）”来解释这些粒子的分辨率，纳米打印技术相当于每英寸产生10万个打印点，而普通的橡皮版印刷术目前只能以每英寸1500 个打印点的分辨率工作。

　为了展示其方法的有效性和多功能性，科研人员打印了一张罗伯特·弗鲁德在17世纪创作的太阳图（炼金术士的黄金图腾）。这种打印方法在每个点上精确地放置了一个粒子，从而首次用单色素粒子打印出了最小巧的艺术作品。

[b]
　纳米打印的应用[/b]

　　在生物医学中，这种打印技术将用于打印生物功能微型球体的大阵列，这些微型球体可以探测和识别人体内特定的细胞或生物标志。一个微型球可以迅速扫描癌细胞或心脏病发作标志。作为新的定点检测诊断设备，功能性微型球体的常规阵列仅需要很少量的样本就可以激活快速和自动读取功能。

　　纳米粒子还可以与光发生相互作用。利用新的方法，可以打印具有新属性的光学材料，比如，用于光电子设备的光学材料。纳米打印可以创造出“可调谐元材料（Metamaterial）”，这种材料中的打印结构的大小与光的波长相当，因此它们的表现如同一个具有特异属性的单一镜头。

　　此外，这种方法还有望打印半导体。在一次实验中，科研人员成功放置了用于培植半导体纳米线的催化型种子粒子。这种纳米线有望成为未来微芯片晶体管的候选材料。

[b]　　纳米级打印[/b]

　　苏黎士纳米图案研究小组的托拜厄斯·克劳斯解释称：“在传统的照相凹版印刷术中，需要使用刮墨刀来弥补印刷板的凹陷墨点，这样一来色素粒子会很容易被驱散。在我们的高分辨率印刷术中，定向式自装配程序控制着印刷板或模板上的纳米粒子的排列。整个组件被打印在目标表面上，因此粒子的位置被精确地保留下来，其分辨率比传统的印刷术高三个数量级。”

　　科研人员考察了多种印刷模板几何学，其中包括产生密实型纳米粒子线的线性几何学（可用于分子电子学）；作为纳米线培育种子的黄金粒子的规则排列和任意排列（比如印制的太阳图复制品）。测量大面积区域上的排列偏差所用的远程精度与微接触印刷术很相似。下一步将更好地完善这种方法从而实现更高的精确度，这也是微电子设备的大规模整合以及打印更小粒子被必需的。

出处：中国科技信息网Chinainfo。