A study of ZnO doped PDMS towards boosting of triboelectric energy harvester performance

Abstract

In this article, a study of ZnO doping in poly-dimethyl-siloxane (PDMS) polymer, which is used as one tribo layer in tribo-electric energy harvesters (TEG) is corroborated to enhance the electrical properties, open circuit voltage (Voc)and short circuit current (ISC). A parallel plate device configuration of metal-to-dielectric approach is carried out making use of copper as metal and PDMS polymer with ZnO doping as a dielectric film. The double sided copper tape of 99.99 % purity and 60 μm thickness is used to realize the top tribo layer whiledielectric PDMS polymer film with ZnO doping of 8 wt%, 13 wt%, and 18 wt% is spin coated at 1000 rpm on single side copper coated FR4 substrate to make the bottom tribo-electic layer. The mechanical force is applied in tapping mode on top layer by Universal Testing Machine (UTM). The prototype device is characterized by Agilent DSO, which revealed peak output voltage of 15 V, 20 V, 30 V, and 41 V and peak-to-peak output voltage 38 V, 50 V, 60 V, and 69 V in pure PDMS, PDMS+8 % ZnO, PDMS+13 % ZnO, and PDMS+18 % ZnO respectively. The output peak current is obtained 9 nA, 20 nA, 30 nA, and 32 nA and peak-to-peak current 31 nA, 49 nA, 51 nA, and 60 nA respectively. The performance of ZnO doped PDMS TEG has increased adequately, up to 68.44 % Of Voc and 71.87 % of Isc.with respect to pure PDMS. A scanning electron microscope (SEM) is used to confirm polymer film morphology and ZnO doping percentage in PDMS is validatedby energy dispersive X-ray spectroscopy.