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Polymer Nanocomposites-Based Wearable Smart Sensors
Published in Anandhan Srinivasan, Selvakumar Murugesan, Arunjunai Raj Mahendran, Progress in Polymer Research for Biomedical, Energy and Specialty Applications, 2023
Mohammed Khalifa, C. Shamitha, Sawan Shetty, Anandhan Srinivasan
Piezoelectric sensors are based on the piezoelectric effect, wherein the material produces electrical charges upon the application of external load or pressure and vice versa. When the pressure is applied to the sensor, the electric dipoles reorient themselves in one direction. As a result, the surface charge changes and produces voltage (Richardson, 1989). Piezoelectric wearable sensors are used for tactile sensing, motion detection, monitoring pulse pressure, body mobility, and physical activity monitoring (Chung, Lee, Lee, & Kim, 2017; Karan et al., 2018; Khalifa, Mahendran, & Anandhan, 2019; Spanu et al., 2016). Piezoelectric materials such as lead zirconate titanate (PZT) (S. Zhang, Zhang, Wang, Wang, & Pan, 2019), zinc oxide nanowires (Dahiya et al., 2018), barium titanate (BaTiO3) (Alluri et al., 2017), and poly(vinylidene fluoride) (PVDF) (Khalifa & Anandhan, 2019) are amongst the most common materials used for the wearable technology. Piezoelectric sensors are already in the market and are available for various applications. However, the main drawback of these sensors is their charge-leaking characteristic, which could be detrimental for sensing low-frequency signals. Piezoelectric sensors are seen to be potential materials for wearable devices because of their self-powered sensing capabilities.
Sensors and Sensing Techniques
Published in Stanislaw Zurek, Characterisation of Soft Magnetic Materials Under Rotational Magnetisation, 2017
A typical piezoelectric sensor has a wide frequency bandwidth, ranging up to 1 MHz (depending on size and mass). The response through frequency range is non-linear, with a maximum sensitivity around the self-resonant frequency of the sensor. For instance, the sensor Micro30 has an operating range up to 400 kHz, with the resonant frequency at 125 kHz or 225 kHz (depending on the type of definition) (Mistras, 2011). The sensor is 10 mm diameter and has a height of 12 mm (Figure 3.70).
Intelligent Parking Solutions in the IoT-based Smart Cities
Published in Fadi Al-Turjman, Intelligence in IoT-enabled Smart Cities, 2018
Fadi Al-Turjman, Arman Malekloo
Piezoelectric sensors detect mechanical stress that is induced by the pressure or the vibration of objects passing over them by converting them into an electric charge. The value of the generated voltage is directly proportional to the weight of the vehicle exerting a force on the sensors. For accurate measurements multiple sensors should be used, however, they are susceptible to high amount of pressures and temperature [15, 40].
Identification of crack by vibration analysis and restoration of dynamic response in beams using PZT sensor/actuator
Published in Nondestructive Testing and Evaluation, 2023
Goutam Roy, Brajesh Panigrahi, G Pohit
At the same time, a numerous research reveal the importance of such smart material in the field of detection and repair of crack in different elements, which acts under dynamic as well as under static loading. Roy et al. [15] introduced a simple approach to employ PZT bending sensors to detect crack in statically loaded beam. It is clearly shown how easily a piezoelectric patch can find a discontinuity in rotational displacement, which induces due to a crack. Fukunaga et al. [16] proposed a method to detect crack by way of piezoelectric sensors and consequently proposed an iterative method to measure the severity of the damage. Sumant and Maity [17] presented a new approach to detect crack in short simply supported beam, where two PZT patches are bonded on the top and bottom faces of the beam. The integrated beam patch specimen is studied with different crack depths, under gradually applied static loading through three-point bending machine. Subsequently, an effective way is approached to solve the inverse problem. Refs. [18–22] reflects how a piezoelectric material can be employed as an effective actuator to reduce the effect of crack in beams under static loading.
Partial Discharge Detection and Localization in Power Transformers based on Acoustic Emission: Theory, Methods, and Recent Trends
Published in IETE Technical Review, 2021
Viral B. Rathod, Ganesh B. Kumbhar, Bhavesh R. Bhalja
Due to the high cost of the commercial acoustic sensor used for PD detection, the application of low-cost piezoelectric diaphragms (buzzers) for PD detection in the transformer is proposed in [60], [61]. The feasibility study of a low-cost piezoelectric sensor for PD detection in transformer compared to the conventional acoustic sensor is presented in [60]. The experimental result shows that a low-cost piezoelectric sensor has lower sensitivity compared to the conventional acoustic sensor. However, the similar behaviour of the time domain and frequency domain signals of both sensors indicate the feasibility of a low-cost piezoelectric sensor for PD detection in the transformer. The feasibility study of a low-cost sensor for identifying the level of PD evolution in the transformer is presented in [61]. The experimental results show that with an increase in the voltage level, the amplitude of the detected PD signal by low-cost sensor increases. This result verifies that the proposed low-cost sensor identifies the level of PD evolution.
Review of energy-consumption measuring techniques for the flotation process
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2018
Gan Cheng, Chuanxiang Zhang, Yijun Cao, Zhendong Jiang
Piezoelectric sensors and torque sensors are often used to measure the fluid in the flotation process. A piezoelectric sensor is a device that uses the piezoelectric effect to measure changes in pressure, acceleration, temperature, strain, or force by converting the signal into an electrical charge. Therefore, the velocity fluctuation of the fluid and the local energy dissipation are related to the voltage output signal. A torque sensor is a device for measuring and recording the torque in a rotating system such as an engine, crankshaft, gearbox, transmission, rotor, bicycle crank, or cap torque tester. It is relatively easy to measure static torque. On the other hand, it is a bit difficult to measure dynamic torque since it normally requires the transfer of some effect (electric or magnetic) from the shaft whose torque is being measured to a static system.