# Investigation of Blade Printing Technique for Nano-Structuring Piezoelectric Polymer Ink in a Porous Anodic Aluminum Oxide

## TL;DR

Researchers used a blade printing technique to create nanostructured piezoelectric polymer films inside aluminum oxide pores, improving energy harvesting performance.

## Contribution

A modified blade printing method was developed to fill AAO nanopores with piezoelectric polymer, enabling precise nanostructuring for enhanced charge generation.

## Key findings

- Nanostructured AAO/PVDF-TrFE samples generated up to 395 mV RMS voltage at 17 Hz with aluminum electrodes.
- At high frequencies, gold-electroded samples produced 680 mV RMS voltage.
- Uniform PVDF-TrFE layers showed 15% lower voltage output across all frequencies.

## Abstract

In this work, we investigated the use of a piezoelectric flexible device for energy harvesting. The main goal of the study was to fill the nanostructured pores of anodic aluminum oxide (AAO) films with piezoelectric polymer (PVDF-TrFE) via a modified conventional screen printing technique using blade printing. In this way, it is possible to obtain a composite from nanostructured thin films of polymer nanorods that shows improved charge generation ability compared to other non-nanostructured composites or pure (non-composite) aluminum with similar dimensions. This behavior is due to the effect of the highly developed surface of the material used to fill in the AAO nanopore template and its ability to withstand the application of higher mechanical loads to the structured piezoelectric material during deformation. The contact blade print filling technique can produce nanostructured piezoelectric polymer films with precise geometric parameters in terms of thickness and nanorod diameters, at around 200 nm, and a length of 12 μm. At a low frequency of 17 Hz, the highest root-mean-square (RMS) voltage generated using the nanostructured AAO/PVDF-TrFE sample with aluminum electrodes was around 395 mV. At high frequencies above 1700 Hz, the highest RMS voltage generated using the nanostructured AAO/PVDF-TrFE sample with gold electrodes was around 680 mV. The RMS voltage generated using a uniform (non-nanostructured) layer of PVDF-TrFE was 15% lower across the whole frequency range.