Osmotic Propulsion: The Osmotic Motor

CBET-0754967 Brady智力优点：设计能够将储存的化学能转化为运动的纳米发动机是纳米技术的一个关键变革性挑战，特别是对于能够自主运行的纳米发动机。最近的实验表明，通过使用表面催化反应，即所谓的催化纳米马达，可以为纳米尺度和微米尺度的物体的运动提供动力。造成这种运动的确切机制尚不清楚，尽管已经提出了一些想法。这个项目涉及一个非常简单的机制提出：渗透推进。表面化学反应产生反应性物质和产物物质的局部浓度梯度，其在马达上产生净渗透力。电机能够通过化学反应利用一直存在的随机热运动来实现定向自主运动。这项研究表明，这种“渗透”电机是可能的，并解决了这样的问题：多快可以电机移动？它能产生多大的力量？它能承载多少“货物”？它能泵出多少液体？它的运动是如何被控制和引导的？可以使用哪些化学物质？这种渗透马达的效率是多少？更广泛的影响：渗透推进提供了一种非常简单和通用的方法，将化学能转化为机械运动和功。通过渗透推进利用胶体系统中的随机热运动可以彻底改变微流体和纳米器件的设计和操作，应用于材料的定向自组装，微处理器和纳米处理器的热管理以及化学和生物传感器的设计和操作。这项研究将为可用作渗透马达的胶体颗粒的构建和操作提供明确的处方。如果我们希望实现未来设想的许多纳米级技术，就必须进行这项基础性和变革性的研究：微型医疗“纳米机器人”，可以在细胞水平上进入人体内的疾病并修复它;或者可以通过“芯片实验室”设备中的微通道感知它们的方式，搅拌或分离纳米升的化学品。或者甚至是一个纳米马达，它能感应到特定分子的入侵，游向它，并在这个过程中关闭一个通道，触发生物污染物的警报开关。只要正确理解和利用该尺度下的运动物理学，这些类型的装置中的任何一种都是可能的。最后，对自主马达的研究可能有助于更普遍地理解生物系统中发生的化学机械转导，并创造出模仿生物体的新型人造马达，可以用来执行有用的任务。

CBET-0754967BradyIntellectual Merit: The design of nanoengines that can convert stored chemical energyinto motion is a key transformative challenge of nanotechnology, especially for nano-engines that can operate autonomously. Recent experiments have demonstrated that it is possible to power the motion of nanoscale and microscale objects by using surface catalytic reactions so-called catalytic nanomotors. The precise mechanism responsible for this motion is not known, although a number of ideas have been put forth. This project involves a very simple mechanism is proposed: osmotic propulsion. A surface chemical reaction creates local concentration gradients of the reactive and product species which generate a net osmotic force on the motor. The motor is able to harness the ever present random thermal motion via a chemical reaction to achieve directed autonomous motion. This research demonstrates that such an 'osmotic' motor is possible and addresses such questions as: How fast can the motor move? How large of a force can it generate? How much 'cargo' can it carry? How much fluid can it pump? How can its motion be controlled and directed? What chemistry can be used? What is the efficiency of such an osmotic motor?Broader Impact: Osmotic propulsion provides a very simple and general means to convert chemical energy into mechanical motion and work. Exploiting the random thermal motion in colloidal systems via osmotic propulsion can revolutionize the design and operation of microfluidic and nanodevices, with applications in directed self-assembly of materials, thermal management of micro- and nanoprocessors, and the design and operation of chemical and biological sensors. This research will provide explicit prescriptions for the construction and operation of colloidal particles that can be used as osmotic motors. This fundamental and transformative study must be undertaken if we wish to enable many of the nano-scale technologies envisioned for the future: tiny medical 'nanobots' that can access human illness inside the body, at the cellular level, and repair it. Or devices that can sense their way through micro channels in 'lab on a chip' devices, stirring or separating nano-liters of chemicals. Or even a nano-motor that senses intrusion of a specific molecule, swims toward it, and closes a channel in the process triggering an alarm switch for biological contaminants. Any of these types of devices is possible provided the physics of motion at that scale is correctly understood and utilized. And finally, studies of autonomous motors may help to understand more generally chemomechanical transduction as occurs in biological systems, and also create novel artificial motors that mimic living organisms and which can be harnessed to perform useful tasks.