Fabrication of nanoporous free standing anodic alumina using two-step anodization for applicability in microhydraulic system as nano filter using surface acoustics

Abstract The current trend in nano/micro structured array fabrication for a variety of applications in microsystems development nanoporous anodic alumina (Al2O3) gained tremendous attention. In this research paper, Freestanding (FS) nanoporous anodic alumina were fabricated using a two-step anodization technique. Nanoporous honeycomb structure having an average 85 nm pore diameter and 135 nm distance between pores were achieved by electrochemical anodization at identical constant DC voltage 60 V. Nanoporous membrane thickness 0.25 µm were obtained with 36% porosity. Scanning electron microscopy (SEM) analysis investigation was done and it confirms honeycomb nanoporous structures were formed on the surface of FS AAO membrane. Additionally, Energy dispersive x-ray spectroscopy (EDS) microanalysis was conducted for the FS AAO membrane to analyze the chemical component after anodization. Finally, fabricated FS nanoporous AAO membrane response was presented under electrical excitation to enables its applicability as a nano filter in microhydraulic systems.