压电圆盘弯曲式矢量水听器的设计

介绍一种采用三迭圆片作为敏感元件的矢量水听器——压电圆盘弯曲式矢量水听器的设计方法 ,并给出根据此方法设计制作的压电圆盘弯曲式矢量水听器的性能指标——自由场开路电压灵敏度和指向性图的实验测试结果 :自由场电压灵敏度为 - 2 14.5dB(0dB =1V/μPa ,测试频率 10 0 0Hz) ;指向性图的分辨力kd >2 0dB。     

基于压电加速度计的同振型矢量水听器的设计

介绍一种压电加速度计在新型水声接收换能器———同振型矢量水听器设计中的应用方法。叙述了采用压电加速度计设计同振型矢量水听器的理论依据,并给出根据此方法设计制作的同振型矢量水听器的自由场开路电压灵敏度和指向性图测试结果:自由场电压灵敏度为-190～-200dB(0dB=1V/μPa,测试频率1000Hz),指向性图分辨力kd>20dB。     

一种新型压阻式硅微仿生矢量水听器的设计

介绍了一种新型的基于压阻效应的硅微仿生矢量水听器,详细叙述了该矢量水听器的结构设计方法,利用有限元软件ANSYS对矢量水听器结构进行了模态分析,采用振动台标定与低频校准装置测试相结合的方法对水听器进行测试,并给出了检测单元的加速度频响特性曲线和声压灵敏度曲线,以及矢量水听器在水下测试的接收灵敏度曲线和指向性图的测试结果.通过此实验方法,不仅验证了该矢量水听器设计的合理性,而且验证了它适用于低频检测,应用于水声探测具有一定的可行性.实验证明,该矢量水听器的接收灵敏度在500 Hz时达到-189.6 dB(0 dB=1 V/μPa),并具有良好的"8"字形的指向性.     

一种新型压阻式硅微仿生矢量水听器的设计

介绍了一种新型的基于压阻效应的硅微仿生矢量水听器,详细叙述了该矢量水听器的结构设计方法,利用有限元软件ANSYS对矢量水听器结构进行了模态分析,采用振动台标定与低频校准装置测试相结合的方法对水听器进行测试,并给出了检测单元的加速度频响特性曲线和声压灵敏度曲线,以及矢量水听器在水下测试的接收灵敏度曲线和指向性图的测试结果。通过此实验方法,不仅验证了该矢量水听器设计的合理性,而且验证了它适用于低频检测,应用于水声探测具有一定的可行性。实验证明,该矢量水听器的接收灵敏度在500Hz时达到-189.6dB(0dB=1V/μPa),并具有良好的“8”字形的指向性。     

一种MEMS同振柱型仿生矢量水听器的研制

提出了一种结合MEMS技术、仿生原理和压阻原理的同振柱型矢量水听器,即由二维仿生水听器和声压水听器组合而成的柱体。在声学理论基础上详细介绍了该水听器的封装设计及制作过程,在国防水声一级计量站对该矢量水听器进行校准实验,实验结果表明:该同振型矢量水听器的工作频带范围为0～3 kHz;X通道灵敏度-177.9 dB(2 kHz),Y通道灵敏度-175.4 dB(2 kHz),声压通道灵敏度-175.8 dB(2 kHz);具有很好的"8"字指向性;可承受3 MPa压力。此新型MEMS同振矢量水听器适用于民用船只避障,渔业捕捞,海洋勘探等领域。     

同振型三轴光纤矢量水听器设计与实现

设计制作一款同振式光纤矢量水听器，其外形为圆球形。光纤矢量水听器是由弹性体、质量块、固定件、底部球壳、球壳上盖、干涉仪组成。外形尺寸为φ100mm。实验测得在100Hz～1kHz频段内.，加速度灵敏度≥40dBre1rad/g，.指向性>25dB，对矢量水听器探头在声学水池中测试加速度灵敏度，通过测试加速度灵敏度为平均435dBre1rad/g，灵敏度波动小于±15dB。指向性指标进行测试，我司版本矢量水听器的指向性表现出了“∞”字型图样，指向性约为26dB，该矢量水听器加速度灵敏度高一致性好，使用方便，满足工程应用需求。     

单片集成四元阵列式MEMS矢量水听器的研究

针对当前对MEMS矢量水听器高可靠性迫切要求,设计了2×2单片集成四元阵列式MEMS矢量水听器,以保证其中一个敏感微结构失效损坏或工作不正常时,水听器仍能正常工作.结合ANSYS软件对阵列敏感微结构进行了仿真分析;设计了该微结构的加工工艺流程;最后,对阵列式MEMS矢量水听器进行水声校准测试.测试结果表明:阵列式水听器可靠性明显提高,灵敏度达到-179 dB(0 dB =1V/μPa),具有良好的“8”字指向性.     

新型三维MEMS矢量水听器的设计

根据国内对高灵敏度、低频小体积三维矢量水听器的需求,提出了一种仿鱼侧线纤毛的MEMS三维矢量水听器。该水听器采用多纤毛结构分别用来接收X、Y与Z方向的声信息,采用ANSYS进行仿真,静力分析得出了布放压阻的合理位置,谐响应分析得出该结构的固有频率在1.5 kHz左右;驻波桶校准测试结果表明:该水听器的灵敏度范围在-200 dB到-180 dB左右;在25 Hz～2 000 Hz频段内具有良好的频响特性;指向性分辨率大于等于30 dB,具有良好的"8"字形指向性。     

纤毛式MEMS矢量水听器的优化设计与测试

针对目前MEMS仿生矢量水听器灵敏度偏低和现有封装结构的固有机械特性对芯片拾振特性影响很大的问题,对该结构水听器从两个方面进行优化设计,一是提出一种新型纤毛材料碳棒代替光纤,二是提出嵌入式透声帽封装结构.首先理论分析纤毛和封装对水听器灵敏度和频带的影响,并用ANSYS软件对其进行仿真,最后对加工的水听器样机进行频响和指向性测试.测试结果表明:在25 ～300 Hz,优化后的水听器灵敏度提高了5 dB;在300～ 1000 Hz,优化后水听器灵敏度提高10 dB,优化后水听器的共振峰明显后移,拓宽了水听器的工作频带,且具有良好的指向性,为水听器进一步的发展和工程应用奠定了基础.     

一种小型矢量阵优化波束方法研究

在小型声纳平台中由于单个矢量水听器所含的振速传感器具有自然指向性,其组成的矢量阵较传统水听器阵有优越性,但单个矢量水听器的自然指向性波束较宽,组成的矢量阵的-3dB束宽和旁瓣级不够理想。该文利用单个矢量传感器的声压、振速信息联合处理形成较好指向性,并用于矢量阵获得良好的阵列效果,同时分析了该方法对线阵和圆阵的影响。仿真结果表明当线阵的阵元间距和圆阵半径都为0．5米时,矢量阵接收低频信号所形成的波束图中-3dB束宽在以25°内,第一旁瓣级低于-60dB,这证明了该文的方法是有效的。     

Modeling and characterization of a micromachined artificial hair cell vector hydrophone

In the paper, a micromachined artificial vector hydrophone arises from a biological inspiration, the fish hair cell is presented. It is desirable that the application of piezoresistive effects combined with ingenious bionic structure and MEMS technology may improve the low-frequency sensitivity of the vector hydrophone as well as its miniaturization. Modeling processes for realizing the artificial hair cell hydrophone, along with preliminary characterization results in terms of sensitivity, frequency response and directivity patterns are also introduced. The microstructure of the sensor consists of four vertical cantilever beams with attached rigid plastic cylinder in the center of the structure. By locating eight piezoresistors logically formed the Wheatstone bridges; they can detect two components of underwater acoustic signal simultaneously. The prepared vector hydrophone has been measured in the standing wave field finally. The experiment results show that the vector hydrophone has good low-frequency characteristic, the free-field voltage sensitivity is −197.2 dB (0 dB = 1 V/μPa) at 400 Hz with a about 2 dB one-third octave positive slope over the 40–400 Hz bandwidth. The depth of pits of the directivity pattern is about 34.6 dB.     

A new hybrid fabrication process for a high sensitivity MEMS microphone

A novel multi-layer stacking capacitive type microphone is designed in this study based on theoretical analysis and numerical simulations, while fabricated via two standard stable silicon-based MEMS processes—PolyMUMPs and SOIMUMPs. The adoption of two standardized processes helps greatly to increase yield rate. The sensitivity of the microphone is first determined by an analytical model based on an equivalent circuit, which is followed by finite element (FEM) analyses on the capacitance value, static pull-in voltage and dynamic characteristics. Based on the developed analytical model, varied dimensions of the microphone are optimized and then the performance is validated by analytical simulations. In the next step, micro-fabrication of the microphone is accomplished using two standard processes, PolyMUMPs and SOIMUMPs provided by MEMSCAP. Experiments are conducted to acquire the information of pull-in voltage for safe operation and frequency response in sensitivity for performance evaluation. In the static case, experimental results show a good agreement with the analytical results with 90 Mpa residual stress assumed. As for dynamic validation, the frequency response is measured in an anechoic room adopting the exciting frequency as the audible range from 100–10 kHz. The measured sensitivity is as around 0.78 and 1.7 mV/Pa from 100 to 10 kHz, under the biases of 2 and 4.5 V, respectively. Within the audible frequency range, the proposed device maintains the loss as less as 2.7 dB (ref. to V/Pa), under 3 dB—the commonly acceptable drop within audible frequency range.     

Piezoelectric cantilever microphone and microspeaker

A micromachined piezoelectric cantilever transducer, which works both as a microphone and as a microspeaker, has been fabricated and tested. The 2000×2000×4.5 μm³ cantilever has a zinc oxide (ZnO) piezoelectric thin film on a supporting layer of low-pressure chemical-vapor-deposited (LPCVD) low-stress silicon nitride. A highlight of the fabrication process, which may also be relevant for other micromachined structures, is the technique for producing a flat, multilayer cantilever. The measured microphone sensitivity is fairly constant at 3 mV/μbar in the low frequency range and rises to 20 mV/μbar at the lowest resonant frequency of 890 Hz. The 3 mV/μbar sensitivity is the highest reported to date for a microphone with a micromachined diaphragm. When measured into a 2 cm³ coupler with 4 V(zero-peak) drive, the microspeaker output sound pressure level (SPL) is 75 dB at 890 Hz. It increases to approximately 100 dB SPL at 4.8 kHz with 6 V(zero-peak) drive. The measured microphone frequency response agrees well with the results of an ABAQUS simulation     

MEMS仿生矢量水听器封装结构的设计与研究

针对MEMS仿鱼侧线矢量水听器提出三种封装结构,即采用聚氨酯材料制成的透声帽封装结构,透声帽内衬笼状支撑体的封装结构,透声帽内衬瓣状支撑体的封装结构采用ANSYS有限元建立三维封装模型并进行模态仿真,得出其固有频率分别为875 Hz、2 926 Hz、3006 Hz.采用Virtual.lab acoustic进行声衰减仿真并通过试验验证最终得出:内衬支撑体的封装结构,其有效带宽响应比无支撑体的透声帽封装结构宽2.2 kHz左右,同时,实验表明瓣状支撑体的收缩瓣状部分具有聚能效应,这种封装结构的水听器灵敏度比其他两种封装结构在相同频率点处高8 dB～ 12 dB.     

基于丁腈橡胶帽封装的MEMS仿生水听器的设计

针对现有封装结构会对灵敏度造成一定程度的损失,使现有水听器的灵敏度小于水听器芯片裸测灵敏度的问题,改用了透声性能好、耐腐蚀的丁腈橡胶(NBR)制作的透声帽,并对现有的矢量水听器的封装外壳进行相应的优化设计。该封装结构的水听器的共振频率降低到50 Hz以下,水听器所感兴趣的频段(50 Hz~4 kHz)不会受到封装谐振的干扰,拓宽了水听器的工作频段。该封装的灵敏度提高到几乎与裸片的灵敏度一致,达到(-170±2)dB,并优化金属管壳的圆盘的尺寸,即水听器最大径,由36 mm缩小至28 mm,使水听器的封装进一步小型化。     

Advancements in technology and design of NEMS vector hydrophone

This paper reports on recent developments to improve the performance of hair vector hydrophone by means of several technological advancements in the fabrication procedures and corresponding sensor design. With fish’s lateral line organs as prototypes, NEMS (Nano-Electromechanical System) vector hydrophone with directivity has been designed. This paper describes the meso-piezoresistance effect of resonant tunneling thin-film, and the NEMS hydrophone based on this effect is highly sensitive and small size. The application of bionics structure may improve the low-frequency sensitivity of hydrophone. The calibration test shows that NEMS vector hydrophone’s receiving sensitivity is up to −170 dB (0dB = 1 V/μPa), has a good directional pattern in the form of “8” shape. The sea test shows that the direction of target can be detected by single NEMS vector hydrophone. In the anechoic tank, it has been verified that NEMS vector hydrophone can track the trajectory of the moving target.     

A new measurement microphone based on MEMS technology

This paper presents a new type of measurement microphone that is based on MEMS technology. The silicon chip design and fabrication are discussed, as well as the specially developed packaging technology. The microphones are tested on a number of key parameters for measurement microphones: sensitivity, noise level, frequency response, and immunity to disturbing environmental parameters, such as temperature changes, humidity, static pressure variations, and vibration. A sensitivity of 22 mV/Pa (-33 dB re. 1 V/Pa), and a noise level of 23 dB(A) were measured. The noise level is 7 dB lower than state-of-the-art 1/4-inch measurement microphones. A good uniformity on sensitivity and frequency response has been measured. The sensitivity to temperature changes, humidity, static pressure variations and vibrations is fully comparable to the traditional measurement microphones. This paper shows that high-quality measurement microphones can be made using MEMS technology, with a superior noise performance.