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

INTRODUCTION: Recent advancements in 3D printing technology allow us to design and fabricate customized droplets cells for localized electrochemical patterning. OBJECTIVES: In this study, 3D printed solution-flow type microdroplet cell (Sf-MDC) is proposed for localized anodizing of two different regions on Al surface. The effect of printing orientation on 3D printing parameters is elucidated to minimize the resin consumption, printing time and material wastage. The capability of Sf-MDC to fabricate porous alumina patterns with adjustable pore size and thickness is explored by varying the length of Pt wire inside each capillary. METHODS: The Sf-MDC was optimally fabricated using 3D printer at the highest possible resolution. The Al specimens were electropolished in 13.6 kmolm(−3) CH3COOH/2.56 kmolm(−3) HClO(4) at 278 K and 28 V for 145 s. 0.22 kmolm(−3) oxalic acid (COOH)(2) solution was prepared for anodizing. The specimen was set on pulse-XYZ stage controller and anodized (at 50 V and 323 K) using the Sf-MDC. RESULTS: Anodizing with Sf-MDC resulted in the formation of two uniformly sized porous alumina lines on the specimen. Porous alumina lines exhibited similar pore geometry, interpore distance and pores arrangement, suggesting uniform supply of current to both the droplets. Layered-type cross-sectional structure with each layer having a thickness of 2.7 mm was formed for both the porous alumina lines. By varying the length of Pt wire inside each capillary, porous alumina lines with different porous structure and oxide thickness were simultaneously fabricated. CONCLUSIONS: Simultaneous anodizing with Sf-MDC can be applied for fast fabrication of porous alumina filters with different porous structure and for various patterning applications.