Naeli Kianoush, Brand Oliver
School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA.
Rev Sci Instrum. 2009 Jun;80(6):063903. doi: 10.1063/1.3143567.
A novel technique is developed to cancel the effect of environmental parameters, e.g., temperature and humidity, in resonant mass sensing. Utilizing a single resonator, the environmental cancellation is achieved by monitoring a pair of resonant overtones and the effective sensed mass in those overtones. As an eminent advantage, especially compared to dual-mode temperature compensation techniques, the presented technique eliminates any need for previously measured look-up tables or fitting the measurement data. We show that a resonant cantilever beam is an appropriate platform for applying this technique, and derive an analytical expression to relate the actual and effective sensed masses on a cantilever beam. Thereby, it is shown that in applying the presented technique successfully, the effective sensed masses must not be the same in the investigated pair of resonance overtones. To prove the feasibility of the proposed technique, flexural resonance frequencies of a silicon cantilever are measured before and after loading with a strip of photoresist. Applying the presented technique shows significant reductions in influence of environmental parameters, with the temperature and humidity coefficients of frequency being improved from -19.5 to 0.2 ppm degrees C(-1) and from 0.7 to -0.03 ppm %RH(-1), respectively.
开发了一种新技术，用于消除谐振质量传感中环境参数（如温度和湿度）的影响。利用单个谐振器，通过监测一对谐振泛音以及这些泛音中的有效传感质量来实现环境消除。作为一个显著优点，特别是与双模温度补偿技术相比，该技术无需先前测量的查找表或拟合测量数据。我们表明，谐振悬臂梁是应用该技术的合适平台，并推导了一个解析表达式，以关联悬臂梁上的实际和有效传感质量。由此表明，在成功应用该技术时，所研究的一对谐振泛音中的有效传感质量必须不同。为了证明所提技术的可行性，在加载一条光刻胶前后测量了硅悬臂梁的弯曲共振频率。应用该技术显示环境参数的影响显著降低，频率的温度系数和湿度系数分别从-19.5提高到0.2 ppm/°C和从0.7提高到-0.03 ppm/%RH。
