Flexible lead-free piezoelectric nanofiber composites based on BNT-ST and PVDF for frequency sensor applications

Composites, Fabrication and Application of Polyvinylidene Fluoride for Flexible Electromechanical Devices: A Review

“…Researchers at Kyungnam University have synthesized an excellent lead-free piezoelectric material [9], which is a kind of flexible lead-free piezoelectric nanofiber composite of BNT-ST((1-x)Bi0.5Na0.5TiO3-xSrTiO) ceramics and PVDF polymer, which were fabricated by electrospinning. By measuring the functional relationship between the output frequency and voltage of the PVDF nanofiber composite containing BNT-ST ( Figure 3c) [9], the piezoelectric properties of the composite and the sensitivity of the piezoelectric output to frequency are substantially improved. This is because BNT-series materials can overcome large coercive field defects and exhibit strong piezoelectric properties [69][70][71][72][73].…”

“…Xiaohe et al [97] fabricated (BTO)/P(VDF-TrFE) composite nanofibers by electrospinning and were able to distinguish and sense the movement of walking ants and the energy of a free-falling ball as low as 0.6 µJ (Figure 8c). Sang et al [9] fabricated flexible lead-free piezoelectric nanofibers composed of PVDF and BNT-ST ceramic by electrospinning. The output voltage measurement system is a frequency function for the BNT-ST/PVDF nanofiber composite module (Figure 8d).…”

“…Kunming et al [136] fabricated nanocomposite fiber mats by electrospinning graphene nanosheets, barium titanate, and PVDF, obtaining as high as 11 V of opencircuit voltage (Figure 8f,g)). (d) Optical photo and SEM of BNT-ST/PVDF nanofiber composite [9]; (e) PVDF strain sensor for measuring the force of the string [135]; (f) Mechanical movement in the primitive phase and the bending phase [136]; (g) Optical image and output voltage generated by human movement [136].…”

“…(a) Variation of stored power with time and SEM of PLZT particles dispersed in the PVDF matrix[63]; (b) The relationship between output voltage and applied forces with different frequencies[64]; (c) Relationship between output frequency and voltage of PVDF nanofiber composite containing BNT-ST[9]; (d) Optical diagram PVDF/BTZO hybrid film[68]; (e) SEM of PVDF/BTZO hybrid film[68].…”

Fabrication and Characterization of Aligned Flexible Lead-Free Piezoelectric Nanofibers for Wearable Device Applications

“…On the other hand, flexible piezoelectric polymers such as polyvinylidenefluoride (PVDF) and P(VDF-trifluoroethylene(TrFE)), are poor in piezoelectricity and some other ways to improve the piezoelectric properties of PVDF nanofibers were studied [ 3 ]. In response to these challenges, composites of lead-free ceramics and polymers have been developed and development of nanofiber-based composites has also been studied to improve flexibility [ 4 , 5 , 6 ].…”