Vertically aligned zinc oxide nanowires electrodeposited within porous polycarbonate templates for vibrational energy harvesting.

A piezoelectric nanogenerator has been fabricated using a simple, fast and scalable template-assisted electrodeposition process, by which vertically aligned zinc oxide (ZnO) nanowires were directly grown within a nanoporous polycarbonate (PC) template. The nanowires, having average diameter 184 nm and length 12 μm, are polycrystalline and have a preferred orientation of the [100] axis parallel to the long axis. The output power density of a nanogenerator fabricated from the as-grown ZnO nanowires still embedded within the PC template was found to be 151 ± 25 mW m(-3) at an impedance-matched load, when subjected to a low-level periodic (5 Hz) impacting force akin to gentle finger tapping.

Template-Assisted Hydrothermal Growth of Aligned Zinc Oxide Nanowires for Piezoelectric Energy Harvesting Applications.

A flexible and robust piezoelectric nanogenerator (NG) based on a polymer-ceramic nanocomposite structure has been successfully fabricated via a cost-effective and scalable template-assisted hydrothermal synthesis method. Vertically aligned arrays of dense and uniform zinc oxide (ZnO) nanowires (NWs) with high aspect ratio (diameter ∼250 nm, length ∼12 μm) were grown within nanoporous polycarbonate (PC) templates. The energy conversion efficiency was found to be ∼4.

Quantitative analysis and optimization of gravure printed metal ink, dielectric, and organic semiconductor films.

Here we demonstrate the optimization of gravure printed metal ink, dielectric, and semiconductor formulations. We present a technique for nondestructively imaging printed films using a commercially available flatbed scanner, combined with image analysis to quantify print behavior. Print speed, cliché screen density, nip pressure, the orientation of print structures, and doctor blade extension were found to have a significant impact on the quality of printed films, as characterized by the spreading of printed structures and variation in print homogeneity.