SBIR Phase II: Fast-Response, High Sensitivity MEMS based NOx Emission Sensor

这个小型企业创新研究（SBIR）二期项目将开发用于柴油发动机和其他稀燃燃烧系统的氮氧化物（NOx）传感器。这项创新将独特的基于sic的压电双晶片微谐振器化学检测技术与NOx敏感材料相结合，开发出一种能够在恶劣的发动机排放环境中工作的排放控制NOx传感器。在第一阶段，通过组装一个初步原型，在热机排放的环境中进行测试，证明了NOx传感器的可行性，并展示了1 ppm NOx检测，响应时间为1秒，在400 μ aC下稳定运行。第二阶段的研究目标是改进传感器，包括双晶片谐振器、氮氧化物敏感涂层、包装和控制电子设备，以实现更高的温度操作，5年的使用寿命，并在不同浓度的其他废气中可靠地检测1 ppm的氮氧化物。将进行广泛的稳定性和寿命测试，以确定和解决潜在的降解机制，如中毒、污垢、碳沉积和材料相互扩散。该原型机包括集成加热器、温度传感器、控制电子设备和电源/数据接口，将在发动机试验台运行，以验证在实际排气环境中的性能。该项目的更广泛的影响/商业潜力在于它能够加速使用清洁柴油和可再生柴油燃料的汽车的采用和使用，这是一种低风险、高影响的方式，既可以减少污染排放，又可以减少美国对外国能源供应的依赖。柴油发动机的温室气体排放量通常比汽油动力汽车少20%。然而，它们也会产生大量的氮氧化物（NOx），这是一种导致烟雾和酸雨的污染物。虽然现有的技术可以处理和消除这种氮氧化物污染，但它需要一个具有灵敏度和响应时间的高温兼容传感器，而这在目前的商业上是不存在的。NSF SBIR第二阶段项目将开发一种能够满足汽车行业对柴油发动机排放传感器的需求的NOx传感器，用于实时车载诊断和减排，使车辆符合将于2013年生效的新环境法规。随着消费者越来越多地选择这些更环保、更经济的汽车，清洁柴油发动机的广泛采用将减少温室气体排放和对石油的依赖。

This Small Business Innovation Research (SBIR) Phase II project will develop a nitrogen oxide (NOx) sensor for diesel engine and other lean-burn combustion systems. This innovation combines unique SiC-based piezoelectric bimorph microresonator chemical detection technology with NOx sensitive materials, to develop an emissions control NOx sensor capable of operating in harsh engine emissions environments. The feasibility of the NOx sensor was demonstrated in Phase I by assembling a preliminary prototype, testing it in environments characteristic of hot engine emissions, and demonstrating 1 ppm NOx detection with 1 second response times and stable operation at 400?aC. The Phase II research objectives are to refine the sensor, including the bimorph resonator, NOx sensitive coatings, packaging and control electronics, to achieve higher temperature operation, 5 year lifetime, and reliable detection of 1 ppm NOx in the presence of varying concentrations of other exhaust gases. Extensive stability and life testing will be performed to identify and address potential degradation mechanisms such as poisoning, fouling, carbon deposition and materials inter diffusion. The prototype, including integrated heater, temperature sensor, control electronics and power/ data interface, will be operated in engine test stands to demonstrate performance in actual exhaust environments. The broader impact/commercial potential of this project lies in its ability to accelerate the adoption and use of automobiles that use clean diesel and renewable diesel fuels, which is a low-risk and high-impact way of reducing both polluting emissions and US dependency on foreign energy supplies. Diesel engines typically produce up to 20% less greenhouse gas emissions than a comparable gasoline powered vehicle. However, they also produce a significantly higher amount of nitrogen oxides (NOx), a pollutant that causes smog and acid rain. Although the technology exists to treat and eliminate this NOx pollution, it requires a high temperature compatible sensor with sensitivity and response time that does not exist commercially today. This NSF SBIR Phase II program will develop a NOx sensor capable of meeting the needs of the automotive industry for a diesel engine emissions sensor for both real-time on-board diagnostics and emissions reduction, bringing vehicles into compliance with new environmental regulations coming into effect in 2013. Enabling the wider adoption of clean diesel engines will reduce both greenhouse gas emissions and dependency on petroleum, as consumers increasingly choose these greener and more cost-effective vehicles.