Piezoelectric PVDF

Figure 1 Schematic diagram of the production line for piezoelectric PVDF tube...

Hadimani RL, B ayramol DV, Soin N, Shah TH, Qian L, Shi S, et al. Continuous production of piezoelectric PVDF fibre for e-textile apphcations. Smart Mater Struct 2013 22(7) 075017. 

Currently, the physiological significance of piezoelectricity in many biopolymers is not well imderstood, but it is beheved that such electromechanical phenomena may have a distinct role in biochemical processes. For example, it is known that electric polarization in bone influences bone growth (38). In one study, a piezoelectric PVDF film was wrapped around the femiu- of a monkey. Within weeks, a remarkable formation of new bone was observed. The motion of the animal caused deformation of the film, which produced a neutrahzing ionic current in the surroimding tissue. This minute fluctuating current appears to stimulate the metabolic activity of bone cells and leads to the proliferation of bone. 

Harris, G.R., Preston, R.C. and DeReggi, A.S. (2000) The impact of piezoelectric PVDF on medical ultrasound exposure measurements, standards, and regulations, IEEE Trans. Ultrason. Ferroelec. Freq. Contr., 47, 1321-35. 

Zeng, M., S.W. Or and H.L. W. Chan (2010), Magnetic field-induced strain and mag-netoelectric effects in sandwich composite of ferromagnetic shape memory Ni-Mn-Ga crystal and piezoelectric PVDF polymer. IEEE Transactions on Ultrasonics Eerroelectrics and Frequency Control, 57(10) pp. 2147-2153. 

The existenee of the two classes of ferroelectric and piezoelectric polymers, PVDF and its eopolymers and odd-numbered nylons, makes it possible to develop polymer-polymer eomposite systems. Ferroelectric and piezoelectric PVDF-nylon 11 bilaminates and nylon 11-PVDF blends were studied by Su (1992) and Gao et al. (1999), respectively. Significant enhancements in ferroelectric and piezoelectric properties were observed in both polymer-polymer composite systems. Interfacial polarization plays an important role for the enhancement. 

Fig. 6 Photograph of a transparent piezoelectric PVDF loudspeaker on polyethersulfone support with polythiophene electrode layers (Reprinted with permission (Sugimoto et al. 2009))...

P. Th. A. Klaase, Low-inquency and ultrasonic applications on piezoelectric PVDF films, Ferroelectrics 60 215 (1984). 

A further improvement in piezoelectrically stimulated bone-healing has been provided by experimental work on the repair of fracture using piezoekctric cndomedullary ostbeosynthesis [58]. Sleinman pins have been purposely prepared to lodge a piezoelectric PVDF tubular layer. After the generation of fracture in rat femurs, the pins were insetted into the medullary cavity of bone. 

Some flexible devices are based on electrospun nanofibrous web of piezoelectric PVDF and its copolymer for sensing and energy harvesting. This section will give... 

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