Self-powered sound detection and recognition sensors based on flexible polyvinylidene fluoride-trifluoroethylene films enhanced by in-situ polarization

2020 ◽  
Vol 306 ◽  
pp. 111970
Author(s):  
Zhen Guo ◽  
Shuai Liu ◽  
Xiaoran Hu ◽  
Qian Zhang ◽  
Fei Shang ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Sound Detection ◽  
Self Powered ◽  
Detection And Recognition

scholarly journals Flexible Multiscale Pore Hybrid Self-Powered Sensor for Heart Sound Detection

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4508
Author(s):  
Boyan Liu ◽  
Liuyang Han ◽  
Lyuming Pan ◽  
Hongzheng Li ◽  
Jingjing Zhao ◽  
...  
Keyword(s):  
Piezoelectric Coefficient ◽  
Heart Sound ◽  
Piezoelectric Materials ◽  
Ferroelectric Material ◽  
Flexible Sensor ◽  
Β Phase ◽  
Short Processing Time ◽  
Sound Detection ◽  
Corona Poling ◽  
Self Powered

This research introduces an idea of producing both nanoscale and microscale pores in piezoelectric material, and combining the properties of the molecular β-phase dipoles in ferroelectric material and the space charge dipoles in order to increase the sensitivity of the sensor and modulate the response frequency bandwidth of the material. Based on this idea, a bi-nano-micro porous dual ferro-electret hybrid self-powered flexible heart sound detection sensor is proposed. Acid etching and electrospinning were the fabrication processes used to produce a piezoelectric film with nanoscale and microscale pores, and corona poling was used for air ionization to produce an electret effect. In this paper, the manufacturing process of the sensor is introduced, and the effect of the porous structure and corona poling on improving the performance of the sensor is discussed. The proposed flexible sensor has an equivalent piezoelectric coefficient d33 of 3312 pC/N, which is much larger than the piezoelectric coefficient of the common piezoelectric materials. Experiments were carried out to verify the function of the flexible sensor together with the SS17L heart sound sensor (BIOPAC, Goleta, CA, USA) as a reference. The test results demonstrated its practical application for wearable heart sound detection and the potential for heart disease detection. The proposed flexible sensor in this paper could realize batch production, and has the advantages of flexibility, low production cost and a short processing time compared with the existing heart sound detection sensors.

Electrospun polyvinylidene fluoride nanofiber mats for self-powered sensors

2017 ◽  
Author(s):  
Debarun Sengupta ◽  
Ajay Giri Prakash Kottapalli ◽  
Jianmin Miao ◽  
Chee Yee Kwok
Keyword(s):  
Polyvinylidene Fluoride ◽  
Self Powered ◽  
Nanofiber Mats

scholarly journals Tunable In Situ 3D-Printed PVDF-TrFE Piezoelectric Arrays

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5032
Author(s):  
Alec Ikei ◽  
James Wissman ◽  
Kaushik Sampath ◽  
Gregory Yesner ◽  
Syed N. Qadri
Keyword(s):  
3D Printing ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Mechanical Strain ◽  
Pressure Sensors ◽  
Strain Ratio ◽  
Ex Situ ◽  
Order Of Magnitude ◽  
3D Printed

In the functional 3D-printing field, poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) has been shown to be a more promising choice of material over polyvinylidene fluoride (PVDF), due to its ability to be poled to a high level of piezoelectric performance without a large mechanical strain ratio. In this work, a novel presentation of in situ 3D printing and poling of PVDF-TrFE is shown with a d33 performance of up to 18 pC N−1, more than an order of magnitude larger than previously reported in situ poled polymer piezoelectrics. This finding paves the way forward for pressure sensors with much higher sensitivity and accuracy. In addition, the ability of in situ pole sensors to demonstrate different performance levels is shown in a fully 3D-printed five-element sensor array, accelerating and increasing the design space for complex sensing arrays. The in situ poled sample performance was compared to the performance of samples prepared through an ex situ corona poling process.

Thin-Film PVDF Sensor Based Monitoring of Cutting Forces in Peripheral End Milling

2012 ◽  
Author(s):  
Lei Ma ◽  
Shreyes N. Melkote ◽  
John B. Morehouse ◽  
James B. Castle ◽  
James W. Fonda ◽  
...  
Keyword(s):  
Thin Film ◽  
Polyvinylidene Fluoride ◽  
End Milling ◽  
Beam Theory ◽  
Dynamic Strain ◽  
Data Logging ◽  
Sensor Material ◽  
Sensor Module ◽  
Sensor Signals

A sensor module that integrates a thin film Polyvinylidene Fluoride (PVDF) piezoelectric strain sensor and an in situ data logging platform has been designed and implemented for monitoring of feed and transverse forces in the peripheral end milling process. The module, which is mounted on the tool shank, measures the dynamic strain(s) produced in the tool and logs the data into an on-board card for later retrieval. The close proximity between the signal source and the PVDF sensor(s) minimizes the attenuation and distortion of the signal along the transmitting path and provides high-fidelity signals. It also facilitates the employment of a first principles model based on Euler-Bernoulli beam theory and the constitutive equations of the piezoelectric sensor material to relate the in situ measured PVDF sensor signals to the feed and transverse forces acting on the tool. The PVDF sensor signals are found to compare well with the force signals measured by a platform type piezoelectric force dynamometer in peripheral end milling experiments.

In-situ formation of polyvinylidene fluoride microspheres within polycaprolactone electrospun mats

Polymer ◽  
2020 ◽  
Vol 186 ◽  
pp. 122087 ◽  
Author(s):  
Gianluca Balzamo ◽  
Xiyu Zhang ◽  
Wolfram A. Bosbach ◽  
Elisa Mele
Keyword(s):  
Polyvinylidene Fluoride ◽  
In Situ Formation

Direct In Situ Hybridized Interfacial Quantification to Stimulate Highly Flexile Self-Powered Photodetector

2018 ◽  
Vol 122 (23) ◽  
pp. 12177-12184 ◽  
Author(s):  
Yuvasree Purusothaman ◽  
Nagamalleswara Rao Alluri ◽  
Arunkumar Chandrasekhar ◽  
Venkateswaran Vivekananthan ◽  
Sang-Jae Kim
Keyword(s):  
Self Powered

scholarly journals A constant current triboelectric nanogenerator arising from electrostatic breakdown

2019 ◽  
Vol 5 (4) ◽  
pp. eaav6437 ◽  
Author(s):  
Di Liu ◽  
Xing Yin ◽  
Hengyu Guo ◽  
Linglin Zhou ◽  
Xinyuan Li ◽  
...  
Keyword(s):  
Mechanical Energy ◽  
Constant Current ◽  
Triboelectric Nanogenerator ◽  
The Novel ◽  
Electrostatic Induction ◽  
Self Powered ◽  
Output Characteristics ◽  
Paradigm Shifting ◽  
The Internet Of Things

In situ conversion of mechanical energy into electricity is a feasible solution to satisfy the increasing power demand of the Internet of Things (IoTs). A triboelectric nanogenerator (TENG) is considered as a potential solution via building self-powered systems. Based on the triboelectrification effect and electrostatic induction, a conventional TENG with pulsed AC output characteristics always needs rectification and energy storage units to obtain a constant DC output to drive electronic devices. Here, we report a next-generation TENG, which realizes constant current (crest factor, ~1) output by coupling the triboelectrification effect and electrostatic breakdown. Meanwhile, a triboelectric charge density of 430 mC m−2 is attained, which is much higher than that of a conventional TENG limited by electrostatic breakdown. The novel DC-TENG is demonstrated to power electronics directly. Our findings not only promote the miniaturization of self-powered systems used in IoTs but also provide a paradigm-shifting technique to harvest mechanical energy.

Automatic Recognition of Porcine Abnormalities Based on a Sound Detection and Recognition System

2019 ◽  
Vol 62 (6) ◽  
pp. 1755-1765
Author(s):  
Sunan Zhang ◽  
Jianyan Tian ◽  
Amit Banerjee ◽  
Jiangli Li
Keyword(s):  
Large Scale ◽  
Rapid Development ◽  
Recognition System ◽  
Automatic Recognition ◽  
Farm Animals ◽  
Support Vector ◽  
Support Vector Data Description ◽  
Detection Accuracy ◽  
Sound Detection ◽  
Detection And Recognition

Abstract. With the rapid development of large-scale breeding, manual long-term monitoring of the daily activities and health of livestock is costly and time-consuming. Therefore, the application of bio-acoustics to automatic monitoring has received increasing attention. Although bio-acoustical techniques have been applied to the recognition of animal sounds in many studies, there is a dearth of studies on the automatic recognition of abnormal sounds from farm animals. In this study, an automatic detection and recognition system based on bio-acoustics is proposed to hierarchically recognize abnormal animal states in a large-scale pig breeding environment. In this system, we extracted the mel-frequency cepstral coefficients (MFCC) and subband spectrum centroid (SSC) as composite feature parameters. At the first level, support vector data description (SVDD) is used to detect abnormal sounds in the acoustic data. At the second level, a back-propagation neural network (BPNN) is used to classify five kinds of abnormal sounds in pigs. Furthermore, improved spectral subtraction is developed to reduce the noise interference as much as possible. Experimental results show that the average detection accuracy and the average recognition accuracy of the proposed system are 94.2% and 95.4%, respectively. The effectiveness of the proposed sound detection and recognition system was also verified through tests at a pig farm. Keywords: Abnormal sounds, MFCC, SSC, States of pigs, SVDD.

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