NANO: EMT: Revolutionary 3D Nanoarchitectures to Organize the Assembly of Computing Elements

NANO：EMT：用于组织计算元件组装的革命性 3D 纳米架构

• 批准号: 0523290
• 负责人: Nadrian Seeman
• 金额: $ 30万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-15 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0523290&HistoricalAwards=false
• 关键词: NANO; EMT; Revolutionary; 3D; Nanoarchitectures

Improvements in computational capability have entailed making the components smaller and smaller, to the point where we are reaching the limits of the current top-down fabrication methodologies. Furthermore, fabrication methods currently in place are inherently limited to two dimensional arrangements of components. With the research to be pursued under this award, we plan to address both of those problems: We will develop methods to assemble computing components from the bottom-up, using chemical methods. In addition, we will extend our ability to assemble computational elements from two dimensions to three dimensions.How do we plan to accomplish these ambitious goals? We will use the most effective and selective self-assembling system that is found in nature -- DNA. We are all aware that DNA serves as the genetic material of living organisms, from bacteria to humans. One of the key features of DNA that enables it to fulfill this role is complementarity between the two strands of the double helix: If one side of the helix contains a unit known as an A, the other side will always have another unit know as a T; likewise, two further complementary units known as G and C work in the same way. We now live in an era when it is very easy to synthesize DNA strands with particular sequences on them, so we can program a given strand on one side, and then make its complementary strand on the other side. Furthermore, DNA is a nanoscale object, with a width of about 2 nm, and a helical repeat of about 3.5 nm. In addition, DNA is the molecule whose intermolecular interactions are the most readily programmed, from the perspectives both of affinity (which molecules will bind to which others), and structure (what will they look like when they combine). This intermolecular programming is accomplished by using short single-stranded segments on the ends of each molecule, which are called 'sticky ends'.But wait. Nature already makes linear DNA molecules in profusion. Synthetic molecules would just be relatively short 'lines' of matter, so what use would they be? The advantage of synthetic DNA molecules is that they can be programmed to associate into branched, rather than linear molecules. Thus, joining a bunch of linear DNA molecules together can lead to longer lines, but joining branched molecules together can lead to connected networks of DNA. In the past, we have built a variety of two dimensional crystalline arrays with specific patterns; to do this we have designed DNA strands to form two dimensional motifs that could they self-assembled using sticky ends. In the research to be pursued under this award, we will design and self-assemble motifs that will form motifs that self-assemble to produce three dimensional arrays, related to conventional crystals, such as sugar crystals, except that their repeating units will be much larger. We will characterize these molecules using the standard method for examining three-dimensional matter, x-ray crystallography.How does the assembly of three dimensional DNA crystals relate to revolutionary computing? We have just discussed that DNA has outstanding architectural properties. However, it does not seem well-suited to serve as a computational component. By contrast, there are numerous newly discovered nanoscale-sized systems, such as carbon nanotubes or quantum dots that would seem to be ideal for computational purposes, if only we could organize them into circuitry for our purposes. Once we are able to assemble DNA into three-dimensional arrangements, we will undertake to use its architectural features to act as scaffolding in three dimensions for electronic components such as these. Thus, we will combine the outstanding architectural properties of DNA, which we know how to control, with demonstrated outstanding electronic components to form circuitry in three dimensions. This achievement ultimately will lead to extremely dense memory units and extremely rapid computation.

计算能力的提高需要使部件越来越小，以至于我们达到了当前自上而下制造方法的极限。此外，目前的制造方法固有地局限于元件的二维排列。随着这一奖项下的研究，我们计划解决这两个问题：我们将开发方法，自下而上地使用化学方法组装计算组件。此外，我们将把我们组装计算元素的能力从二维扩展到三维。我们计划如何实现这些雄心勃勃的目标？我们将使用自然界中发现的最有效和最有选择性的自组装系统--DNA。我们都知道，DNA是生物体的遗传物质，从细菌到人类。DNA能够发挥这一作用的关键特征之一是双螺旋的两条链之间的互补性：如果螺旋的一侧包含一个被称为A的单位，另一侧将始终有另一个被称为T的单位；同样，另外两个被称为G和C的互补单位的工作方式也是相同的。我们现在生活在一个很容易合成带有特定序列的DNA链的时代，所以我们可以在一边对给定的链进行编程，然后在另一边制作它的互补链。此外，DNA是一个纳米级的物体，宽度约2 nm，螺旋重复约3.5 nm。此外，从亲和力(哪些分子将与哪些其他分子结合)和结构(当它们结合时会是什么样子)的角度来看，DNA是其分子间相互作用最容易编程的分子。这种分子间编程是通过在每个分子的末端使用短的单链片段来完成的，这些片段被称为“粘性末端”。大自然已经制造出大量的线性DNA分子。人工合成的分子只是相对较短的物质“线”，那么它们有什么用呢？合成DNA分子的优势在于，它们可以通过编程结合成分支分子，而不是线形分子。因此，将一群线性DNA分子连接在一起可能会导致更长的线条，但将分支分子连接在一起可能会导致DNA网络连接。在过去，我们已经建立了各种具有特定图案的二维晶体阵列；为了做到这一点，我们设计了DNA链来形成二维图案，这些图案可以使用粘性末端自组装。在该奖项下进行的研究中，我们将设计和自组装形成主题的主题，这些主题将自组装成与传统晶体(如糖晶体)相关的三维阵列，只是它们的重复单元将大得多。我们将使用检查三维物质的标准方法--X射线结晶学来表征这些分子。三维DNA晶体的组装与革命性的计算有什么关系？我们刚刚讨论过DNA具有突出的建筑特性。然而，它似乎不太适合作为计算组件。相比之下，有许多新发现的纳米级系统，例如碳纳米管或量子点，似乎是计算目的的理想选择，只要我们能将它们组织成符合我们目的的电路。一旦我们能够将DNA组装成三维排列，我们将承诺利用它的建筑特征在三维空间中充当脚手架，用于这些电子元件。因此，我们将把我们知道如何控制的DNA的杰出结构特性与已展示的优秀电子元件结合起来，形成三维电路。这一成就最终将导致极高的存储单元密度和极快的计算速度。