用于液相检测的微机械扭摆谐振器

MEMS Pendulous Resonator Used in Liquid

提出了一种在扭转模态工作的微机械谐振器,与传统的弯曲模态相比,扭转模态能量损耗低,故更适用于液相检测。通过理论建模优化了结构;通过加入合适的补偿电路使谐振器在液体中的Q值达到500;此传感器包含检测扭摆和参比扭摆,对两个摆在闭环下的频率变化进行记录,对两者差分可有效抵消由于温度漂移及非特异性吸附等引起的频率变化。上述结果验证了此种谐振器用于液相检测生物分子的可行性。

A novel MEMS resonator working in the torsional mode is presented. As the energy loss of the torsional mode is low compared to the conventional flexural mode, it is more suitable for working in the liquid. The structure is optimized according to the theory model; the Q-factor of the resonator is improved to 500 by introduction of a feed-back circuit ; a detecting pendulous resonator and a reference one are included in the sensor. Frequency changes of the two resonators, which are both working in the closedloop mode, are recorded. By differencing the two, frequency change due to change of temperature and non-specific adsorption can be offset to a great degree. All the results above have verified the feasibility to use this kind of sensor in detecting bio-moleeules in liquid.