一种MEMS体声波硅谐振器的设计

设计了一种基于SOI衬底工艺的MEMS体声波硅谐振器及其制造方法。利用有限元分析软件对该谐振器进行了模态分析,并针对提高品质因数Q,研究了其损耗机制。结果表明：谐振频率可达108MHz,且取决于硅材料特性和器件尺寸,而品质因数则决定于支撑损耗。最后,从振动模态和传输线模型角度出发,提出了减少支撑损耗提高Q值的可行性方法,包括将支撑梁放置在振动节点处、梁长度设置为弹性波长的1/4及在衬底端设置声波反射器。     

体声波复合谐振器新结构的研究

本文报道了一种由氧化锌薄膜和多晶硅膜片构成的体声波复合谐振器的新结构，与传统制作在硅支撑膜片上的压电复合谐振器不同，多晶硅支撑膜采用表面微机械技术获得，因而是完全平面工艺，不需要双面光刻和背面腐蚀。采用Ｓ枪磁控反应溅射在多晶硅膜片上获得了ｃ轴取向良好的氧化锌薄膜。所得的谐振器的基波工作频率在５６０ＭＨｚ左右，而尺寸小于２５０×２５０μｍ２。     

Reversible Conversion between Schottky and Ohmic Contacts for Highly Sensitive,Multifunctional Biosensors

Schottky and Ohmic contacts–based electronics play an important role in highly sensitive detection of biomolecules and neural electric impulses, respectively. The reversible conversion between these two contacts appears especially important for multifunctional sensing by just one biosensor. Here, Schottky barrier height (SBH) is successfully tuned by triboelectric nanogenerator (TENG) and the same device is made to achieve reversible conversion between Schottky contact and Ohmic contact. In the same Schottky to Ohmic reversible (SOR) biosensor, highly sensitive detections of biomolecule (i.e., neurotransmitter) and neural electric signal are achieved at different contact states. The SOR biosensor reveals the feasibility of using one device to realize multifunctional detection. This work proposes a simple and significant method to achieve reversible tuning between the Schottky contact and Ohmic contact on one device by TENG, which exhibits great potential in developing multifunctional and high‐sensitivity biosensors, rectifiers, and other functional electronic devices.     

基于FDTD的薄膜体声波谐振器的数值分析

提出了基于时域有限差分方法对薄膜体声波谐振器进行数值分析的新方法.利用时域有限差分法理论对压电材料的控制方程和牛顿方程在空间和时间上进行了离散化,通过得到的差分方程直接得出了声场传播的时域数值解.使用该数值方法对薄膜体声波谐振器的电学特性阻抗进行了分析,并将结果与一维Mason模型的解析解进行了比较验证.