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.

scholarly journals Self-powered piezo-bioelectronic device mediates tendon repair through modulation of mechanosensitive ion channels

2020 ◽  
Author(s):  
Marc A. Fernandez-Yague ◽  
Alex Trotier ◽  
Sunny Akogwu Abbah ◽  
Aitor Larrañaga ◽  
Arun Thirumaran ◽  
...  
Keyword(s):  
Piezoelectric Materials ◽  
Tendon Repair ◽  
Ferroelectric Material ◽  
Achilles Tendinopathy ◽  
Body Motion ◽  
Channel Modulation ◽  
Repair Processes ◽  
Bioelectronic Device ◽  
Self Powered ◽  
Specific Tissue

AbstractTendon disease constitutes an unmet clinical need and remains a critical challenge in the field of orthopaedic surgery. Innovative solutions are required to overcome the limitations of current tendon grafting approaches, and bioelectronic therapies are showing promise in the treatment of musculoskeletal disease, accelerating functional recovery through the activation of tissue regeneration signalling pathways (guided regeneration). Self-powered bioelectronic devices, and in particular piezoelectric materials represent a paradigm shift in biomedicine, negating the need for battery or external powering and complementing existing mechanotherapy to accelerate the repair processes. Here, we show the dynamic response of tendon cells to a piezoelectric collagen-analogue scaffold comprised of aligned nanoscale fibres made of the ferroelectric material poly(vinylidenefluoride-co-trifluoroethylene), (PVDF-TrFE). We demonstrate that electromechanical stimulation of tendon tissue results in guided regeneration by ion channel modulation. Finally, we show the potential of the bioelectronic device in regulating the progression of tendinopathy associated processes using a rat Achilles tendinopathy model. This study indicates that body motion-powered electromechanical stimulation can control the expression of TRPA1 and PIEZO2 receptors and stimulate tendon-specific tissue repair processes.

scholarly journals Enhancement of the piezoelectric coefficient in PVDF-TrFe/CoFe2O4 nanocomposites through DC magnetic poling

2021 ◽  
Vol 12 ◽  
pp. 1262-1270
Author(s):  
Marco Fortunato ◽  
Alessio Tamburrano ◽  
Maria Paola Bracciale ◽  
Maria Laura Santarelli ◽  
Maria Sabrina Sarto
Keyword(s):  
Piezoelectric Coefficient ◽  
Vinylidene Fluoride ◽  
Piezoelectric Materials ◽  
Low Cost ◽  
Wearable Sensors ◽  
Polymer Nanocomposite ◽  
Sample Surface ◽  
Β Phase ◽  
Phase Alignment ◽  
Poly Vinylidene Fluoride

In the last years flexible, low-cost, wearable, and innovative piezoelectric nanomaterials have attracted considerable interest regarding the development of energy harvesters and sensors. Among the piezoelectric materials, special attention has been paid to electroactive polymers such as poly(vinylidene fluoride) (PVDF) and its copolymer poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFe), which is one of the most extensively investigated piezoelectric polymers, due to the high β phase content resulting from specific curing or processing conditions. However, to obtain a high piezoelectric coefficient (d33) alignment of the β phase domains is needed, which is usually reached through applying a high electric field at moderate temperatures. This process, usually referred to as electrical poling, requires the deposition of contact electrodes on the sample surface and the use of high-voltage apparatus. In the present work, in order to overcome these constraints, we have produced, characterized, and studied a polymer nanocomposite consisting of CoFe2O4 nanoparticles dispersed in PVDF-TrFe with enhancement of the β phase alignment through an applied DC magnetic field. The magnetic poling was demonstrated to be particularly effective, leading to a piezoelectric coefficient d33 with values up to 39 pm/V. This type of poling does not need the use of a top electrode or of high magnetic fields (the maximum value of d33 was obtained at 50 mT, using a current of 0.4 A) making the PVDF-TrFE/CoFe2O4 nanocomposite suitable for the fabrication of highly efficient devices for energy harvesting and wearable sensors.

scholarly journals All 3D Printed Stretchable Piezoelectric Nanogenerator for Self-Powered Sensor Application

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6748
Author(s):  
Xinran Zhou ◽  
Kaushik Parida ◽  
Oded Halevi ◽  
Shlomo Magdassi ◽  
Pooi See Lee
Keyword(s):  
Piezoelectric Materials ◽  
Mechanical Energy ◽  
Rapid Development ◽  
The Internet ◽  
Electronic Systems ◽  
3D Printed ◽  
Wearable Electronic ◽  
Self Powered ◽  
The Internet Of Things ◽  
Piezoelectric Nanogenerators

With the rapid development of wearable electronic systems, the need for stretchable nanogenerators becomes increasingly important for autonomous applications such as the Internet-of-Things. Piezoelectric nanogenerators are of interest for their ability to harvest mechanical energy from the environment with its inherent polarization arising from crystal structures or molecular arrangements of the piezoelectric materials. In this work, 3D printing is used to fabricate a stretchable piezoelectric nanogenerator which can serve as a self-powered sensor based on synthesized oxide–polymer composites.

A Novel Multi-Directional Nonlinear Piezoelectric Energy Harvester Coupled With Nonlinear Conditioning Circuits

2015 ◽  
Author(s):  
Zhengbao Yang ◽  
Jean Zu
Keyword(s):  
Energy Harvester ◽  
Piezoelectric Materials ◽  
Electrical Energy ◽  
Elastic Rods ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
High Power Output ◽  
Transduction Mechanisms ◽  
Self Powered ◽  
Aluminum Plates

Energy harvesting from vibrations has become, in recent years, a recurring target of a quantity of research to achieve self-powered operation of low-power electronic devices. However, most of energy harvesters developed to date, regardless of different transduction mechanisms and various structures, are designed to capture vibration energy from single predetermined direction. To overcome the problem of the unidirectional sensitivity, we proposed a novel multi-directional nonlinear energy harvester using piezoelectric materials. The harvester consists of a flexural center (one PZT plate sandwiched by two bow-shaped aluminum plates) and a pair of elastic rods. Base vibration is amplified and transferred to the flexural center by the elastic rods and then converted to electrical energy via the piezoelectric effect. A prototype was fabricated and experimentally compared with traditional cantilevered piezoelectric energy harvester. Following that, a nonlinear conditioning circuit (self-powered SSHI) was analyzed and adopted to improve the performance. Experimental results shows that the proposed energy harvester has the capability of generating power constantly when the excitation direction is changed in 360. It also exhibits a wide frequency bandwidth and a high power output which is further improved by the nonlinear circuit.

Self‐Powered Flexible Sensor Based on the Graphene Modified P(VDF‐TrFE) Electrospun Fibers for Pressure Detection

2019 ◽  
Vol 304 (12) ◽  
pp. 1900504 ◽  
Author(s):  
Ping Li ◽  
Libo Zhao ◽  
Zhuangde Jiang ◽  
Mingzhi Yu ◽  
Zhen Li ◽  
...  
Keyword(s):  
Electrospun Fibers ◽  
Flexible Sensor ◽  
Self Powered

Forth Heart Sound Detection Using Backward Time-Growing Neural Network

2019 ◽  
pp. 341-345
Author(s):  
Arash Gharehbaghi ◽  
Amir A. Sepehri ◽  
Ankica Babic
Keyword(s):  
Neural Network ◽  
Heart Sound ◽  
Sound Detection

scholarly journals Development of In-Situ Poled Nanofiber Based Flexible Piezoelectric Nanogenerators for Self-Powered Motion Monitoring

2020 ◽  
Vol 10 (10) ◽  
pp. 3493
Author(s):  
Minjung Kim ◽  
Vignesh Krishnamoorthi Kaliannagounder ◽  
Afeesh Rajan Unnithan ◽  
Chan Hee Park ◽  
Cheol Sang Kim ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
Implantable Devices ◽  
The Past ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
High Bias ◽  
Self Powered ◽  
Increasing Demand ◽  
Piezoelectric Nanogenerators

Energy harvesting technologies have found significant importance over the past decades due to the increasing demand of energy and self-powered design of electronic and implantable devices. Herein, we demonstrate the design and application of in situ poled highly flexible piezoelectric poly vinylidene fluoride (PVDF) graphene oxide (GO) hybrid nanofibers in aligned mode for multifaceted applications from locomotion sensors to self-powered motion monitoring. Here we exploited the simplest and most versatile method, called electrospinning, to fabricate the in situ poled nanofibers by transforming non-polar α-phase of PVDF to polar β- phase structures for enhanced piezoelectricity under high bias voltage. The flexible piezoelectric device fabricated using the aligned mode generates an improved output voltage of 2.1 V at a uniform force of 12 N. The effective piezoelectric transduction exhibited by the proposed system was tested for its multiple efficacies as a locomotion detector, bio-e-skin, smart chairs and so on.

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