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A high quality factor (Q-factor) piezoelectric lead zirconat titanate
(PZT) actuated single crystal silicon cantilever was proposed in this
paper for resonant based ultra-sensitive mass detection. Energy
dissipation from intrinsic mechanical loss of the PZT film was
successfully compressed by separating the PZT actuator from resonant
structure. Exc...
Contexts in source publication
Context 1
... Design and Simulation Figure 1 shows schematic view of the proposed structure. PZT actuators (50×65 µm) were designed on both side of the silicon cantilever and connected to the cantilever via thin hinges (4×10 µm). ...
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... vibration can improve mass detect sensitivity of a resonant cantilever under atmospheric pressure by suppressing the air damping effect [12]. Fig. 10 shows measured and calculated Q-factor dependence on resonant mode at different cantilever geometries. High mode vibration can be successfully achieved by the proposed structure, and greater Q-factor can be obtained as expected for the pursuit of better mass detection ...
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... is noteworthy that in Fig. 10, long cantilever is preferable for high mode vibration. However, the measured Q-factors are still lower than the theoretical calculations. High mode vibration results in large vibration amplitude at the position where cantilever and actuator connects. It leads to large vibration amplitude in PZT actuator, which in turn induces ...
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... [10]. Besides, large vibration amplitude at the actuation hinge also trends to decrease Q sup , because energy may dissipate easily through substrate. For high mode vibration, the actuation position should be close to node-point of the cantilever (the position with no displacement at resonant frequency in theory) to suppress energy dissipation. Fig. 11 shows schematic view of a suggested structure for high mode vibration. This work is still under going. We will report the experimental results in our future publications. ...
Citations
... Any alteration in design of vibrating structures such as double or triple beam, leads to alter Qfactor results in increasing the vibration balancing. The Q-factor is directly correlated with damping, as different damping mechanisms limit the overall Q-factor [45]. Resonators working in a fluid such as gas will have a damping which results in reduction of Q-factor. ...
With the technological advancement in micro-electro-mechanical systems (MEMS), microfabrication processes along with digital electronics together have opened novel avenues to the development of small-scale smart sensing devices with improved sensitivity with a lower cost of fabrication and relatively small power consumption. This article aims to provide the overview of the recent work carried out on the fabrication methodologies adopted to develop silicon based resonant sensors. A detailed discussion has been carried out to understand critical steps involved in the fabrication of the silicon-based MEMS resonator. Some challenges starting from the materials selection to the final phase of obtaining a compact MEMS resonator device for its fabrication have also been explored critically.
In this work, the fabrication process of piezoelectric cantilevers based on aluminum nitride films is presented. The cantilevers were electrically characterized in a vacuum chamber offering the possibility to close-loop control the back pressure from atmospheric conditions down to 10−2 mbar. The quality factor is an important figure of merit to evaluate the performance of micro resonators. In particular, three different modes were detected and analyzed: the first flexural mode, the second flexural mode and the first torsional mode. Among these three investigated modes, the first torsional mode has a higher quality factor compared to the others, which makes this mode more suitable for mass change detection applications as higher sensitivities are feasible. With the first torsional mode, quality factors of up to 4,557 are achievable at low chamber pressure, where the intrinsic damping is the dominating loss mechanism. The quality factor decreased to 1,050 at atmospheric pressure and is limited by viscous losses.
A novel biosensing system based on a micromachined rectangular silicon membrane is proposed and investigated in this paper. A distributive sensing scheme is designed to monitor the dynamics of the sensing structure. An artificial neural network is used to process the measured data and to identify cell presence and density. Without specifying any particular bio-application, the investigation is mainly concentrated on the performance testing of this kind of biosensor as a general biosensing platform. The biosensing experiments on the microfabricated membranes involve seeding different cell densities onto the sensing surface of membrane, and measuring the corresponding dynamics information of each tested silicon membrane in the form of a series of frequency response functions (FRFs). All of those experiments are carried out in cell culture medium to simulate a practical working environment. The EA.hy 926 endothelial cell lines are chosen in this paper for the bio-experiments. The EA.hy 926 endothelial cell lines represent a particular class of biological particles that have irregular shapes, non-uniform density and uncertain growth behaviour, which are difficult to monitor using the traditional biosensors. The final predicted results reveal that the methodology of a neural-network based algorithm to perform the feature identification of cells from distributive sensory measurement has great potential in biosensing applications.
