石英晶体微天平质量检测量研究

Study on Mass Detectable Quantity of Quartz Crystal Microbalance

基于石英晶体微天平质量检测原理，通过分析石英谐振器表面的振动位移，得出决定其电极表面每一点处质量灵敏度的物理量为该点处的振动加速度。在此基础上，基于石英谐振器的巴特沃斯一范·戴克等效电路模型提出一种计算石英晶体谐振器表面振荡幅度的方法，最终得到石英晶体微天平在整个检测过程中能检测到的平均质量。用10MHz的石英晶体微天平进行了数值验证，计算值与其理论上能达到的Pg级检测限基本相吻合。

The vibrational displacement on crystal surface is analyzed on the basis of mass detection principle of quartz crystal microbalance,leading to the conclusion that the physical quantity which determines the mass sensitivity in every point on the electrode surface of the crystal is the acceleration of the crystal vibration in that point. Based on this conclusion, the Butterworth-Van Dyke equivalent circuit of crystal resonator was employed to obtain the computational method of oscillation amplitude on the surface of the quartz crystal microbalance resonator, thus obtaining the average detectable mass of quartz crystal mierobalance in the overall detection process. The experimental result was generally in line with theoretical value （ at the pieogram level） when experimented on a 10 MHz quartz crystal microbalanee.