SBIR Phase II: Development of Particulate Mass and Count Monitoring Instruments Using Micro-Electro-Mechanical Resonant Balances

这个小型企业创新研究第二阶段项目旨在开发体积小、重量轻、价格实惠的个人颗粒物(PM)剂量计。这款目标电池供电的仪器几乎有自来水笔大小，可以夹在衣服上，随身携带。该仪器可以采样周围的空气，将空气中的颗粒物分成几个大小范围，并测量从每个大小范围的空气样本中收集的颗粒物的质量。该仪器由一个微型串级冲击器组成，其中嵌入了微型机电谐振天平作为冲击基板。级联冲击器结构根据空气中颗粒物的大小将其分离，并将其沉积到共振平衡面上。沉积粒子的质量增加会导致微尺度共振天平的共振频率负移。系统中的集成电子学测量谐振器的频率变化，并实时计算沉积质量，从而计算气流中PM的浓度。这类仪器的开发将是一个重大飞跃，不仅是在气溶胶科学和技术方面，而且在微系统技术方面也是如此。该产品将是第一个在感官应用中使用微尺度质量平衡的商业产品，并可能打开其他可能性的大门。该项目更广泛的影响/商业潜力是用于高粉尘工作环境的工业卫生，如煤矿、地下建筑工地、石材和木材切割设施等。直径在几微米及以下的气溶胶颗粒对人类健康构成严重威胁。虽然较大的颗粒物被人类的鼻子和喉咙过滤掉，但更细的颗粒物可以通过血液深入肺部甚至其他器官。众所周知，暴露在高颗粒物浓度下会增加患各种慢性病的风险，降低预期寿命，在极端情况下会导致矽肺等严重无法治疗的疾病。目前可用的颗粒物监测系统不能满足对多功能、方便、高度便携的PM监测仪的需求。更重要的是，该仪器的便利性、可负担性和多功能性允许更严格地监控PM水平，并保护每个工人免受有害PM暴露。这可能是数百万处于高风险环境中的工人的救命稻草。

This Small Business Innovation Research Phase II project aims to develop small size, light-weight, and affordable personal particulate matter (PM) dosimeters. The targeted battery powered instrument almost the size of a fountain pen can be clipped onto clothing and freely carried around. The instrument can sample the surrounding air, separate airborne particles into several size ranges, and measure the mass of particles collected from the air sample in each size range. The instrument is comprised of a miniaturized cascade impactor with micro-electromechanical resonant balances embedded within, as impaction substrates. The cascade impactor configuration separates airborne particles based on their size and deposits them onto the resonant balance surfaces. Added mass of the deposited particles causes a negative shift in the resonant frequency of the microscale resonant balances. Integrated electronics within the system measure the resonator frequency changes and calculate the deposited mass and consequently PM concentration in the air flow in real-time. Development of such instruments would be a major leap forward, not only in aerosol science and technology, but also in microsystems technology. This product would be the first commercial product using a microscale mass balance in a sensory application and could open the door to other possibilities. The broader impact/commercial potential of this project is in industrial hygiene for high dust work environments such as coal mines, underground construction sites, stone and wood cutting facilities, etc. Aerosol particles in the diameter range of a few microns and below pose serious threats to human health. While larger particles are filtered out by human nose and throat, finer particles can reach deep into the lungs and even other organs through the blood stream. It is well established that exposure to high particulate matter concentrations increases risk of various chronic diseases, lowers life expectancy, and in extreme cases leads to severe untreatable conditions such as Silicosis. Currently available particulate monitoring systems cannot address the need for a versatile, convenient, highly portable PM monitor. More importantly, the convenience, affordability, and versatility of the instrument allow tighter monitoring of PM levels and protecting every individual worker from harmful PM exposures. This could be a lifesaver for millions of workers in high risk environments.