SBIR Phase I: MEMS Resonant Nanobalance Dew Point Meters

SBIR第一阶段：MEMS谐振纳米平衡露点计这个小企业创新研究（SBIR）第一阶段项目旨在开发一种基于微机电系统（MEMS）的湿度（露点）测量仪器。痕量水分的测量需要在各种不同的工业部门，包括半导体制造，纯气体供应，大气和气候研究，航空航天，石化加工，发电，空气过滤器和净化器制造，以及其他痕量气体的参考标准的供应。大多数商业上可用的湿度传感器缺乏许多现有应用所需的精度，灵敏度和响应性，或者过于昂贵。所提出的方法利用微机电谐振天平与冷却元件相结合。该仪器将使用标准的冷冻表面技术在谐振天平的表面沉积一层水分来测量露点。沉积的水分的质量引起微谐振器的谐振频率的变化，表明达到露点。因为这种纳米天平能称重到几飞克的沉积水分，所以只需要冷冻非常少量的气体就能沉积足够的水分来指示露点。初步的原型组装、可靠性和响应时间表征将在第一阶段进行。该项目的更广泛的影响/商业潜力是开发比目前在相同价格范围内的现有仪器更准确，响应更快，稳定，坚固和通用的湿度测量仪器。与其他类型的湿度传感器相比，冷冻镜露点传感器通常提供更高的精度。然而，这种装置的反应时间长，其光学传感机制易受碎片和污染的影响。提出的基于MEMS的技术结合了冷冻镜传感器的优点，以及MEMS谐振纳米天平提供的更快的响应和更好的鲁棒性。减少了冷却需求，可以更快地响应水分含量的变化，降低了冷却器的功耗，以及电池供电的现场采样系统等新用途。这种具有重大国家意义的仪器的一个重要直接市场是测量天然气中的水分。在寒冷的气候下，天然气管道中过量的水会冻结管道，使管道无法使用，直到冰点被找到并清除。该仪器具有电池供电、抽查、可靠运行和低成本的特点，将广泛应用于上游天然气管道系统，用于测量保管转移点的湿度。

SBIR Phase I:MEMS Resonant Nanobalance Dew Point MetersThis Small Business Innovation Research (SBIR) Phase I project aims to develop a micro-electro-mechanical-systems (MEMS) based moisture (dew point) measurement instrument. Measurements of trace moisture are needed in a variety of different industrial sectors, including semiconductor manufacturing, pure gas supply, atmospheric and climate research, aerospace, petrochemical processing, power generation, air filter and purifier manufacturing, and supply of reference standards for other trace gases. Most of the commercially available moisture sensors lack the required accuracy, sensitivity, and responsiveness for many existing applications, or are too costly. The proposed approach utilizes micro-electro-mechanical resonant balances coupled with a cooling element. The instrument will measure dew point using the standard chilled surface technique to deposit a layer of moisture on the surface of the resonant balances. Mass of the deposited moisture causes a shift in the resonant frequency of the micro-resonator that indicates reaching the dew point. Because the nanobalances are capable of weighing as little as a few femto-grams of deposited moisture, only a very small amount of gas needs to be chilled to deposit sufficient water to indicate the dew point. Preliminary prototype assembly and reliability and response time characterizations will be performed in this Phase I effort.The broader impact/commercial potential of this project is development of more accurate, responsive, stable, robust, and versatile moisture measurement instruments than currently available instruments at the same price range. Chilled mirror dew point sensors generally provide higher accuracy compared to other categories of moisture sensors. Such devices however suffer from long response times and vulnerability of their optical sensing mechanism to debris and contamination. The proposed MEMS based technology combines the advantages of the chilled mirror sensors along with faster response and improved robustness provided by the MEMS resonant nanobalances. The reduced chilling needs allow for faster response to changes in moisture content, reduced power consumption for the cooler and novel uses such as battery powered spot sampling systems. An important immediate market for the proposed instrument with great national significance is the measurement of moisture in natural gas. In cold climates excess water in the gas pipeline can freeze the pipe shut, rendering the pipeline useless until the frozen point can be located and cleared. The battery powered, spot checking, robust operation and low cost nature of the proposed instrument will allow widespread use in the upstream Natural Gas pipeline system to measure moisture at points of custody transfer.