Towards Intelligent Autonomous Nanoswimmers.

迈向智能自主纳米游泳者。

基本信息

批准号：
EP/G04077X/1
负责人：
Jonathan Howse
金额：
$ 31.42万
依托单位：
University of Sheffield
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2009
资助国家：
英国
起止时间：
2009 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FG04077X%2F1
关键词：
Towards Intelligent Autonomous Nanoswimmers.

项目摘要

This work will combine two clearly defined and characterised physical effects, self-diffusiophoretic nanoswimmers (self- propelled nanoparticles) and pH-responsive hydrogels, to produce a new class of nanoswimmers which are able to swim towards a chemically identified target, mimicking the behaviour of living cells. It will demonstrate for the first time a wholly synthetic version of chemotaxis and will be one of the key building blocks for the soft nanotechnology devices to come, whilst acting as a very simple biomimetic model allowing insight into cell chemotaxis behaviour.The media often presents the image of nanotechnology as a miniaturised submarine navigating through the arteries and veins of the human body. Closer inspections of the physical laws at such dimensions mean the idea of the nanoscale submarine gliding through the body, should be replaced with it struggling through a treacle-like liquid while being constantly hit by nanoscale cannon balls. At the nanoscale water behaves like treacle and a collision with even a single water molecule has an effect.In nature many organisms are able to swim through this nanoscale environment with great success. Bacteria, such as E.Coli, have a corkscrew-like tail which it rotates to push itself through the treacle-like water. In searching for food, they adopt a run and tumble strategy where long runs of straight motion are interrupted by tumbling event where it stops, rotates and then begins to run in a new direction. If this direction is unfavourable it stops, rotates, and runs again.A simple method for producing an synthetic propulsive effect at the nanoscale is to make use of chemical reactions taking place on the surface of a nanoswimmer, such as a spherical particle half coated with a catalyst. Given the right chemical fuel the catalyst will break down the fuel to produce a localised cloud of reaction products which generates a propulsive force on the sphere. However, there is no control over the direction in which they swim.Collisions with the surrounding liquid molecules not only kicks particles it also spins them. It is this spin which causes propelled particles to swim in a random fashion. However, the speed at which it spins is related to its size. The larger the object, the slower it rotates.This research project will develop a new class of nanoswimmers that are able to both propel and steer autonomously. They will be based upon previously successful nanoswimmers possessing a half coated catalyst surface that are able to physically change shape in response to a chemical signal. If the nanoswimmer swims towards a favourable chemical signal, i.e. an acid, it will expand. By doing so, its speed of rotation will be significantly reduced and it will then be able to continue to swim towards the chemical signal. More specifically, microspheres will be produced using the proven technique of electrospraying, where one half of the microsphere will contain the platinum catalyst. This will be the propulsive part of the sphere. The remaining half of the sphere will be made from a pH-responsive polyelectrolyte hydrogel. This material expands and collapses depending upon the pH of the surrounding solution. This volume transition, and hence change in rotational behaviour, will be used to determine the direction in which the nanoswimmer propels itself. It is also possible to have polymer gels which demonstrate a volume change in response to glucose. These will be used to investigate swimmer that steer towards high concentrations of glucose.This exciting research project will be undertaken by a PDRA who will benefit from working and training in such a stimulating and adventurous research area. This grant will form the springboard for future research grant applications and research avenues both theoretically and experimentally, whilst also highlighting the interdisciplinary nature of this project and nanotechnology as a whole.

这项工作将结合两种明确定义和表征的物理效应，自我噬菌学的纳米晶状体（自我推进的纳米颗粒）和pH反应性水凝胶，以产生能够朝着化学鉴定的靶标游泳的新型纳米晶体，并模仿活细胞的行为。它将首次证明完全合成的趋化性，并将成为柔软的纳米技术设备的关键构建块之一，同时充当非常简单的仿生模型，可以深入了解细胞趋化性行为。在这种维度上对物理定律进行了更仔细的检查意味着纳米级潜艇滑过体内的想法，应与纳米般的液体一样挣扎，同时不断被纳米级炮弹击中。在纳米级，水像糖果一样，甚至与单个水分子也有碰撞。从本质上，许多生物都能够在这个纳米级环境中游泳，并取得了巨大的成功。细菌，例如大肠杆菌，具有类似开瓶器的尾巴，它旋转以将自己推到毛状水中。在寻找食物时，他们采用了一种奔跑和翻滚的策略，在该策略中，长时间的直运动被滚动事件打断，即停止，旋转然后开始朝着新的方向运行。如果这个方向不利，它将停止，旋转并再次运行。一种在纳米级产生合成推进效应的简单方法是利用在纳米温度表面发生的化学反应，例如覆盖催化剂一半的球形粒子。鉴于正确的化学燃料，催化剂将分解燃料，以产生局部的反应产品云，从而在球体上产生推进力。但是，无法控制它们游泳的方向。与周围液体分子的汇总不仅踢颗粒，还可以旋转它们。正是这种旋转会导致驱动的颗粒以随机的方式游泳。但是，它旋转的速度与大小有关。物体越大，它旋转的速度就越慢。此研究项目将开发出一种新的纳米温植物类别，这些纳米温植物能够自动推动和引导。它们将基于先前成功的纳米晶体，具有半涂层催化剂表面，能够响应化学信号在物理上改变形状。如果纳米温植物朝着有利的化学信号（即酸）游动，则它将扩展。通过这样做，它的旋转速度将大大降低，然后它将能够继续朝化学信号游泳。更具体地说，将使用经过验证的电喷雾技术生产微球，其中一半的微球将包含铂催化剂。这将是球体的推进部分。其余一半的球体将由pH响应性聚电解质水凝胶制成。该材料取决于周围溶液的pH值。这种体积转变以及旋转行为的变化将用于确定纳米wim驱动器本身的方向。也可以使用聚合物凝胶，该聚合物凝胶表现出响应葡萄糖的体积变化。这些将用于调查游泳者，以指导高浓度的葡萄糖。这一令人兴奋的研究项目将由PDRA进行，该项目将受益于这种令人兴奋和冒险的研究领域的工作和培训。该赠款将在理论上和实验上构成未来的研究赠款应用程序和研究的跳板，同时还强调了该项目的跨学科性质和整个纳米技术。