scholarly journals A Resonant Z-Axis Aluminum Nitride Thin-Film Piezoelectric MEMS Accelerometer

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 589 ◽  
Author(s):  
Jian Yang ◽  
Meng Zhang ◽  
Yurong He ◽  
Yan Su ◽  
Guowei Han ◽  
...  
Keyword(s):  
Thin Film ◽  
Aluminum Nitride ◽  
Resonance Frequency ◽  
Inertial Force ◽  
Relative Sensitivity ◽  
Micro Electro Mechanical Systems ◽  
Static State ◽  
Mems Accelerometer ◽  
Isotropic Etching ◽  
Mems Technology

In this paper, we report a novel aluminum nitride (AlN) thin-film piezoelectric resonant accelerometer. Different from the ordinary MEMS (micro-electro-mechanical systems) resonant accelerometers, the entire structure of the accelerometer, including the mass and the springs, is excited to resonate in-plane, and the resonance frequency is sensitive to the out-plane acceleration. The structure is centrosymmetrical with serpentine electrodes laid on supporting beams for driving and sensing. The stiffness of the supporting beams changes when an out-plane inertial force is applied on the structure. Therefore, the resonance frequency of the accelerometer will also change under the inertial force. The working principle is analyzed and the properties are simulated in the paper. The proposed AlN accelerometer is fabricated by the MEMS technology, and the structure is released by an ICP isotropic etching. The resonance frequency is 24.66 kHz at a static state. The quality factor is 1868. The relative sensitivity of this accelerometer, defined as the shift in the resonance frequency per gravity unit (1 g = 9.8 m/s2) is 346 ppm/g. The linearity of the accelerometer is 0.9988. The temperature coefficient of frequency (TCF) of this accelerometer is −2.628 Hz/°C (i.e., −106 ppm/°C), tested from −40 °C to 85 °C.

scholarly journals Fabrication and Characteristic of a Double Piezoelectric Layer Acceleration Sensor Based on Li-Doped ZnO Thin Film

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 331 ◽  
Author(s):  
Chunpeng Ai ◽  
Xiaofeng Zhao ◽  
Sen Li ◽  
Yi Li ◽  
Yinnan Bai ◽  
...  
Keyword(s):  
Thin Film ◽  
Resonance Frequency ◽  
Piezoelectric Layer ◽  
Rf Magnetron Sputtering ◽  
Micro Electro Mechanical System ◽  
Test Results ◽  
Acceleration Sensor ◽  
Piezoelectric Layers ◽  
Mems Technology ◽  
Doped Zno

In this paper, a double piezoelectric layer acceleration sensor based on Li-doped ZnO (LZO) thin film is presented. It is constituted by Pt/LZO/Pt/LZO/Pt/Ti functional layers and a Si cantilever beam with a proof mass. The LZO thin films were prepared by radio frequency (RF) magnetron sputtering. The composition, chemical structure, surface morphology, and thickness of the LZO thin film were analyzed. In order to study the effect of double piezoelectric layers on the sensitivity of the acceleration sensor, we designed two structural models (single and double piezoelectric layers) and fabricated them by using micro-electro-mechanical system (MEMS) technology. The test results show that the resonance frequency of the acceleration sensor was 1363 Hz. The sensitivity of the double piezoelectric layer was 33.1 mV/g, which is higher than the 26.1 mV/g of single piezoelectric layer sensitivity, both at a resonance frequency of 1363 Hz.

Aluminum Nitride Thin Film Based Surface Acoustic Wave Sensors

2008 ◽  
Author(s):  
A. Kabulski ◽  
V. R. Pagán ◽  
D. Cortes ◽  
R. Burda ◽  
O. M. Mukdadi ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Aluminum Nitride ◽  
Surface Acoustic Wave ◽  
Acoustic Wave Sensors ◽  
Wave Sensors

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

scholarly journals Dynamic Modeling and Anti-Disturbing Control of an Electromagnetic MEMS Torsional Micromirror Considering External Vibrations in Vehicular LiDAR

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 69
Author(s):  
Yong Hua ◽  
Shuangyuan Wang ◽  
Bingchu Li ◽  
Guozhen Bai ◽  
Pengju Zhang
Keyword(s):  
Dynamic Model ◽  
Optical Switching ◽  
Control Method ◽  
Sliding Mode ◽  
Algorithm Design ◽  
Coupling Model ◽  
Micro Electro Mechanical Systems ◽  
Mems Technology ◽  
Torsional Micromirror ◽  
Dynamic Coupling Model

Micromirrors based on micro-electro-mechanical systems (MEMS) technology are widely employed in different areas, such as optical switching and medical scan imaging. As the key component of MEMS LiDAR, electromagnetic MEMS torsional micromirrors have the advantages of small size, a simple structure, and low energy consumption. However, MEMS micromirrors face severe disturbances due to vehicular vibrations in realistic use situations. The paper deals with the precise motion control of MEMS micromirrors, considering external vibration. A dynamic model of MEMS micromirrors, considering the coupling between vibration and torsion, is proposed. The coefficients in the dynamic model were identified using the experimental method. A feedforward sliding mode control method (FSMC) is proposed in this paper. By establishing the dynamic coupling model of electromagnetic MEMS torsional micromirrors, the proposed FSMC is evaluated considering external vibrations, and compared with conventional proportion-integral-derivative (PID) controls in terms of robustness and accuracy. The simulation experiment results indicate that the FSMC controller has certain advantages over a PID controller. This paper revealed the coupling dynamic of MEMS micromirrors, which could be used for a dynamic analysis and a control algorithm design for MEMS micromirrors.

Pulsed DC magnetron sputtered piezoelectric thin film aluminum nitride – Technology and piezoelectric properties

2014 ◽  
Vol 116 (3) ◽  
pp. 034102 ◽  
Author(s):  
C. Stoeckel ◽  
C. Kaufmann ◽  
R. Hahn ◽  
R. Schulze ◽  
D. Billep ◽  
...  
Keyword(s):  
Thin Film ◽  
Aluminum Nitride ◽  
Piezoelectric Properties ◽  
Pulsed Dc ◽  
Piezoelectric Thin Film

Reliability and stability of thin-film amorphous silicon MEMS on glass substrates

2011 ◽  
Vol 1299 ◽  
Author(s):  
P. M. Sousa ◽  
V. Chu ◽  
J. P. Conde
Keyword(s):  
Thin Film ◽  
Resonance Frequency ◽  
Frequency Shift ◽  
Amorphous Silicon ◽  
Structural Damage ◽  
Chemical Vapor ◽  
Stability Study ◽  
Glass Substrates ◽  
Resonance Frequency Shift ◽  
Mems Resonators

ABSTRACTIn this work, we present a reliability and stability study of doped hydrogenated amorphous silicon (n+-a-Si:H) thin-film silicon MEMS resonators. The n+-a-Si:H structural material was deposited using radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) and processed using surface micromachining at a maximum deposition temperature of 110 ºC. n+-a-Si:H resonant bridges can withstand the industry standard of 1011 cycles at high load with no structural damage. Tests performed up to 3x1011 cycles showed a negligible level of degradation in Q during the entire cycling period which in addition shows the high stability of the resonator. In measurements both in vacuum and in air a resonance frequency shift which is proportional to the number of cycles is established. This shift is between 0.1 and 0.4%/1x1011 cycles depending on the applied VDC. When following the resonance frequency in vacuum during cyclic loading, desorption of air molecules from the resonator surface is responsible for an initial higher resonance frequency shift before the linear dependence is established.

Film thickness effects on the fracture of tantalum nitride on aluminum nitride thin film systems

1998 ◽  
Vol 61 (1) ◽  
pp. 107-118 ◽  
Author(s):  
N.R. Moody ◽  
D. Medlin ◽  
D. Boehme ◽  
D.P. Norwood
Keyword(s):  
Thin Film ◽  
Aluminum Nitride ◽  
Film Thickness ◽  
Tantalum Nitride

Solvent-Based Polymer Swelling Characterization for the Development of the Nano/Micro-Particle Polymer Composite MEMS Corrosion Sensor

2014 ◽  
Author(s):  
Feng Pan ◽  
Abdoul Kader Maiga ◽  
Po-Hao Adam Huang
Keyword(s):  
Reaction Products ◽  
Material Transport ◽  
Sensing Element ◽  
Micro Electro Mechanical Systems ◽  
Polymer Swelling ◽  
Corrosion Sensor ◽  
Mems Technology ◽  
New Type ◽  
Oxide Removal

The concept of using Micro-Electro-Mechanical Systems (MEMS) for in-situ corrosion sensing and for long-term applications has been proposed and is currently under development by our research lab. This is a new type of sensing using MEMS technology and, to the knowledge of our team, has not been explored previously. The MEMS corrosion sensor is based on the oxidation of metal nano/micro-particle embedded in elastomeric polymer to form a composite sensing element. The polymer controls the diffusion into and out of the sensor while the corrosion of the metal particles inhibits electrical conduction which is used as the detection signal. The work presented here is based on part of the methods developed for the removal of native and process-induced metal oxides. A major aspect is the study of the swelling dynamics of the polymer matrix (polydimethylsiloxane, PDMS) intended for enhancing material transport of etchants into and reaction products out of the composite during oxide removal. More specifically, the characterization of the swelling of copper particles-PDMS composite samples in liquid solvent baths is presented.

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