PDMS-based Triboelectric and Transparent Nanogenerators with ZnO Nanorod Arrays

Abstract

Vertically-grown ZnO nanorod arrays (NRAs) on indium tin oxide (ITO)-coated polyethylene terephthalate (PET), as a top electrode of nanogenerators, were investigated for the antireflective property as well as an efficient contact surface in bare polydimethysiloxane (PDMS)-based triboelectric nanogenerators. Compared to conventional ITO-coated PET (i.e., ITO/PET), the ZnO NRAs considerably suppressed the reflectance from 20 to 9.7% at wavelengths of 300-1100 nm, creating a highly transparent top electrode, as demonstrated by theoretical analysis. Also, the interval time between the peaks of generated output voltage under external pushing forces was significantly decreased from 1.84 to 0.19 s because the reduced contact area of the PDMS by discrete surfaces of the ZnO NRAs on ITO/PET causes a rapid sequence for triboelectric charge generation process including rubbing and separating. Therefore, the use of this top electrode enabled to operate the transparent PDMS-based triboelectric nanogenerator at high frequency of external pushing force. Under different external forces of 0.3-10 kgf, the output voltage and current were also characterized.

P(VDF-TrFE) Film on PDMS Substrate for Energy Harvesting Applications

“…It is evident that the average voltage and current (solid parts of peaks in each figure) gradually increase with the increase of frequency, while the maximum upper peak voltage remains almost same at around 20 V. The increase in average voltage and current is attributed to the increase in the average surface charge as the bending frequency is increased. This occurs due to the slower discharge rate of the device as compared to the input pulse rate, resulting in a continuous rise in the output voltage and current as frequency is increased [29,30]. At 30 Hz, the peak value of average voltage and current is 5.8 V and 3.2 µA (see Table 2), while the maximum upper peak value of voltage and current is 20 V and 6.5 µA.…”

Mechanically driven luminescence in a ZnS:Cu-PDMS composite

“…The triboelectricity has recently been attracting a great deal of attention since it turned out to be a very promising concept in view of the energy harvesting. [18][19][20] In the energy harvesting device consisting of PDMS and ZnO, the repetitive pushing/separating operations generated positive/negative current signal. 18 PDMS was negatively charged relative to ZnO.…”

“…[18][19][20] In the energy harvesting device consisting of PDMS and ZnO, the repetitive pushing/separating operations generated positive/negative current signal. 18 PDMS was negatively charged relative to ZnO. Assuming ZnO and ZnS to be similar in terms of dielectric property, a certain amount of charge would be accumulated on the interface between the ZnS:Cu particle and the PDMS matrix during the elongation/retreat of the ZnS:Cu-PDMS composite.…”

Controlled fabrication of nanoscale wrinkle structure by fluorocarbon plasma for highly transparent triboelectric nanogenerator

“…In addition, transparent TENGs using indium tin oxide (ITO) or graphene as electrodes have been achieved, which enable applications that require high transparency such as touch screens [31][32][33][34][35] . Our previous work shows that using C 4 F 8 to treat uncured PDMS could deposit fluorocarbon polymer and a wrinkle structure in single step [18][19][20] , which had the advantage of significantly increasing the performance of the flexible TENG.…”

“…Although using a flat surface could provide the highest transparency, the performance of the TENGs will be weakened to some degree 38 . Notably, previous work reported that a PDMS surface with nanopattern sizes o 310 nm could result in high transmittances (above 85%) owing to an effective graded refractive index profile 32,33 . Using a structure of several hundred nanometers provides us with an effective way to realize highperformance and highly transparent TENGs.…”