PDMS/PVDF- MoS2 based flexible triboelectric nanogenerator for mechanical energy harvesting

A green energy generating device that can meet the energy requirements of future technologies without contaminating our environment is increasingly in demand. These devices can harvest energy from ambient sources that are already present in our surroundings. Triboelectric nanogenerator (TENG) has received a lot of attention as a potential sustainable source of power for smart devices, and numerous methods have been explored to enhance its output performance. In this work, we have fabricated a high performance TENG based on MoS2 filled PVDF for harvesting mechanical energy. Effect of MoS2 loading into the PVDF matrix was studied as a function of MoS2 wt% (0, 3, 5, 7, 10%). It has been observed that the fraction of crystalline β-phase and the dielectric constant of PVDF got enhanced after the addition of MoS2. In addition to the dielectric constant, the surface roughness of the MoS2 filled PVDF sample increases, which further contribute to the enhanced triboelectric performance. The TENG device with 7 wt % of MoS2 in PVDF matrix as one of the layer and PDMS as second layer in the vertical contact-separation geometry generates the maximum triboelectric output voltage and current of 189 V and 1.61 μA respectively, while the bare PVDF based TENG generates an output voltage and current of 107 V and 0.88 μA respectively. The TENG with 7 wt % of MoS2 also generates a maximum power density of 104.5 μWcm−2. Further, effect of the tapping frequency and the contact force was also analysed on the PDMS/PVDF-MoS2 based TENG with 7 wt% of MoS2. The triboelectric output voltage and current were also found to be increased with the rise in frequency and the contact force and generated a maximum voltage of ∼211 V. This study proposes an effective approach for enhancing the performance of triboelectric nanogenerator by changing the filler concentration. The fabricated TENG demonstrated the practical application, by powering electronic stopwatch and scientific calculator.