Mertens Johann, Finot Eric, Thundat Thomas, Fabre Arnaud, Nadal Marie-Hélène, Eyraud Vincent, Bourillot Eric
Laboratoire de Physique, Université de Bourgogne, F-21011, Dijon, France
Ultramicroscopy. 2003 Oct-Nov;97(1-4):119-26. doi: 10.1016/S0304-3991(03)00036-6.
The variation in resonance response of microcantilevers was investigated as a function of pressure (10(-2)-10(6)Pa) and temperature (290-390K) in atmospheres of helium (He) and dry nitrogen (N(2)). Our results for a silicon cantilever under vacuum show that the frequency varies in direct proportion to the temperature. The linear response is explained by the decrease in Young's modulus with increasing the temperature. However, when the cantilever is bimaterial, the response is nonlinear due to differential thermal expansion. Resonance response as a function of pressure shows three different regions, which correspond to molecular flow regime, transition regime, and viscous regime. The deflection in flow transition regime resulting from thermal variation has minimal effect on frequency. The frequency variation of the cantilever is caused mainly by changes in the mean free path of gas molecules.
研究了微悬臂梁在氦气（He）和干燥氮气（N₂）气氛中，作为压力（10⁻² - 10⁶ Pa）和温度（290 - 390 K）函数的共振响应变化。我们在真空条件下对硅悬臂梁的研究结果表明，频率与温度成正比。这种线性响应是由杨氏模量随温度升高而降低来解释的。然而，当悬臂梁是双材料时，由于热膨胀差异，响应是非线性的。作为压力函数的共振响应呈现出三个不同区域，分别对应分子流态、过渡态和粘性态。热变化导致的流态过渡区域中的挠度对频率影响最小。悬臂梁的频率变化主要是由气体分子平均自由程的变化引起的。
