Formation of layered structure porous‐type anodic alumina films locally with a solution flow‐type micro‐droplet cell

Abstract

A solution flow-type micro droplet cell with co-axial dual capillary tubes (Sf-MDC) was applied to form porous type anodic alumina film with layered structure at selected areas on aluminium. The anodizing process with different repetition numbers, yielding different oxide layer numbers was performed with the Sf-MDC. The investigation of cross sections of the formed oxide showed that the pore diameter widened at the boundary between layers. From a simulated anodizing process with the Sf-MDC, the reason for this modification of the pores was suggested to be intermittent anodizing with processes of drying up of the solution of the pores and widening at the bottom of the pores.

Small-Area Techniques for Micro- and Nanoelectrochemical Characterization: A Review

“…115 One more thing needs to be considered about the nonlinear relationship between the applied potential and the measured current, which means there is no guarantee that the current will respond to the applied sinusoidal potential. 44 Aside from corrosion research, the MCC technique has also been successfully applied to investigate other interesting aspects, such as electrodeposition of pure metal (e.g., Cu 116−118 and Ni 119,120 ), surface modification, 121 electrochemical machining, 122−125 electrocatalyst materials screening, 70,75,126−128 localized anodizing, 129,130 and thin-film properties characterization. 53,131,132 Furthermore, a multiparallel microcell 120 and devices with an automatic test function 70,131,133 have been developed to achieve high-throughput localized electrochemical characterization, opening a new paradigm of electrochemical analysis.…”

“…Aside from corrosion research, the MCC technique has also been successfully applied to investigate other interesting aspects, such as electrodeposition of pure metal (e.g., Cu − and Ni , ), surface modification, electrochemical machining, − electrocatalyst materials screening, ,,− localized anodizing, , and thin-film properties characterization. ,, Furthermore, a multiparallel microcell and devices with an automatic test function ,, have been developed to achieve high-throughput localized electrochemical characterization, opening a new paradigm of electrochemical analysis.…”

Anodizing—The pore makes the difference

“…Thereby, the pore size is described as proportional to the electrolyte temperature. [118] Ono et al [119] modified the pore size by using polystyrene beads, which were incorporated into the anodic oxide layer. After anodizing, the polystyrene beads were removed, probably by a chemical treatment that is not described in detail.…”

3D printed solution flow type microdroplet cell for simultaneous area selective anodizing

“…Two types of electrochemical droplet cells, i.e. scanning droplet cells [18] , [19] , [20] and solution flow type microdroplet cells [21] , [22] , [23] are commonly used for area-selective anodizing. Recently, Hassel and co-workers have used scanning droplet cell to form anodic oxide lines on Al and Ti specimen for the fabrication of resistors, capacitors, transistors, diodes, rectifiers and memristors [24] .…”