Incorporation of hexagonal boron nitride and multi-walled carbon nanotube for motion sensing triboelectric nanogenerators

In this study, the thermoplastic polyurethane (TPU) composite that incorporates hexagonal boron nitride (h-BN) and multi-walled carbon nanotube (MWCNT) is fabricated and employed as an electrification layer for triboelectric nanogenerators (TENG). Owing to the high elasticity of TPU, the TPU/h-BN/MWCNT composite shows high stretching ability with low Young's modulus of 2∼3 MPa, similar to that of soft tissues. The addition of h-BN efficiently helps construct the conductive network of MWCNT, and the combination of h-BN and MWCNT significantly boosts the dielectric constant of the composite. The mixture of 6 vol% of h-BN and 1.05 vol% of MWCNT exhibits an excellent combination of a real permittivity of 232 and a loss tangent of 2.4, generating the output voltage and current of 47V and 244 nA, respectively. In addition, the increase of resistance is not considerable up to 60 % tensile strain when 1.05 vol% of MWCNT exists in the TPU, and the TPU/h-BN/MWCNT composite presented a stable TENG performances under 60 % strain. Moreover, the TENG made from the TPU/h-BN/MWCNT composite successfully senses a range of complicated hand gestures by producing very distinct output voltages. Thus, it presents promising possibility as a wearable, skin mountable, and self-powered motion sensor.