Human body stimuli-responsive flexible polyurethane electrospun composite fibers-based piezoelectric nanogenerators

Piezoelectric materials derived from piezoelectrically inactive polymers and lead-free functional nanofillers have received a lot of attention for their ability to convert mechanical energy associated with various human body movements into electrical signals. Herein, the fabrication and performance of a novel thermoplastic polyurethane/nanohydroxyapatite electrospun composite membrane-based piezoelectric nanogenerator (PENG) is using polydimethylsiloxane (PDMS). The nanohydroxyapatite (nHA) and oxidized multiwalled carbon nanotube (o-MWCNT) fillers converted a non-piezoelectric PU polymer material into a piezoelectrically active composite material. Compared to pristine electrospun PU, every composite sample showed improved mechanical properties, thermal stability, dielectric properties, and piezoelectric characteristics. Dynamic-contact electrostatic force microscopy (DC-EFM) confirmed the piezo-ferroelectric characteristics of all composite samples. The nHA/o-MWCNT hybrid filler-modified optimized nanofibrous sample (PHAT) showed outstanding dielectric properties and piezoelectric characteristics. The PHAT-based PENG showed the highest stimuli-responsive output voltage in the 0.4–32 V range, whereas the pristine electrospun PU-based PENG showed only an output voltage of 0.08–5.75 V from various stimuli. The flexible PU electrospun composite membrane can be considered a new potential material for harvesting electrical energy from the mechanical energy associated with various human body motions. Graphical abstract