Piezoelectric textile fibres for wearable energy harvesting systems

Piezoelectric textile fibres are important for wearable energy harvesting applications. Piezoelectric melt-spun fibres have been under investigation starting with 2010. While most of research has been carried out on fibres produced from polyvinylidene fluoride (PVDF) which is a widely researched piezoelectric polymer, attempts have been carried out at developing fibres from polypropylene (PP) which has mostly been researched when used in cellular form. Moreover, the piezoelectric behavior of the fibres has until now been characterized, only by the voltage produced by the fibres when they are tested under open circuit conditions. The research presented in this paper, investigated yarn specimens made of polypropylene mixtures with multiwalled carbon nanotubes (MWCNTs) regarding the electric power produced by the yarns. Measurement of the power was carried out using equipment developed by the research team and previously used to measure the power produced by monofilament piezoelectric textile yarns. The result of the current research indicate that the piezoelectric behavior of PP yarns is not affected essentially affected by the addition of MWCNTs and illustrate potential areas for further research of the behavior of piezoelectric PP yarns