Sensors: High Dynamic Range Flow Sensing with Carbon Nanotubes

单壁碳纳米管(SWNT)是一种直径小至1 nm的碳管，由于纳米管的每个原子都在表面，因此是理想的传感候选材料。本项目将研究单壁碳纳米管作为高动态范围流体流量传感器的应用。这项工作是基于最近的发现[Ghosh等人，Science 299,1042(2003)]，即离子液体流过一组纳米管时会在流动方向上产生电压。这一现象将得到验证，初步工作将从以下几个方面展开：1.基于纳米管薄膜的传感器的制备。具有良好控制几何形状的纳米管薄膜将用于测试。这种几何形状将允许更好地控制和建模流动条件2。相关参数的系统变化，如流速和剪切力，样品几何形状，以及外部变量如温度。基于单纳米管的传感器的制作。超长纳米管将采用化学气相沉积的方法生长，并与微流控相结合制成流动装置。我们将研究不同类型的纳米管的流体感应电压以及不同的电化学势。这项工作探索的技术的潜在应用包括将流量传感器集成到芯片实验室设备中，体内生物流体流量传感器，以及低成本、分散的大气和海洋流量传感器。这是一个由传感器倡议NSF 04-522支持的项目。

Abstract0428716James HoneColumbia UniversitySingle-walled carbon nanotubes (SWNTs), tubes of carbon as small as 1 nm in diameter, are ideal candidates for sensing because every atom of a nanotube is at the surface. The use of SWNTs as high dynamic range fluid flow sensors will be investigated in this project. This work is based on the recent discovery [Ghosh et al., Science 299, 1042 (2003)] that flow of an ionic fluid across a collection of nanotubes produces a voltage in the flow direction. This phenomenon will be verified and the initial work extend in the following ways:1. Fabrication of sensors based on thin films of nanotubes. Thin films of nanotubes with well-controlled geometry will be used for testing. This geometry will allow for better control and modeling of flow conditions2. Systematic variation of relevant parameters, such as flow velocity and shear, sample geometry, and external variables such as temperature.3. Fabrication of sensors based on single nanotubes. Ultra-long nanotubes will be grown using chemical vapor deposition, and integrated with microfluidics to make flow devices. The flow-induced voltage will be studied for different types of nanotubes, as well as for varying electrochemical potentials.Potential applications of the technology explored in this work include integration of flow sensors into lab-on-a-chip devices, in-vivo biological fluid flow sensors, and low-cost, dispersed atmospheric and oceanographic flow sensing.This is a project supported under the Sensors Initiative NSF 04-522.