Modelling and Fabrication of Micro-SOFC Membrane Structure

Brigita ABAKEVIČIENĖ; Viktoras GRIGALIŪNAS; Jolita SAKALIŪNIENĖ; Dainius VIRGANAVIČIUS; Kęstutis ŠLAPIKAS; Marius MIKOLAJŪNAS; Sigitas TAMULEVIČIUS

doi:10.5755/j01.ms.20.2.5585

Authors

Brigita ABAKEVIČIENĖ Kaunas University of Technology
Viktoras GRIGALIŪNAS Kaunas University of Technology
Jolita SAKALIŪNIENĖ Kaunas University of Technology
Dainius VIRGANAVIČIUS Kaunas University of Technology
Kęstutis ŠLAPIKAS Kaunas University of Technology
Marius MIKOLAJŪNAS Kaunas University of Technology
Sigitas TAMULEVIČIUS Kaunas University of Technology

DOI:

https://doi.org/10.5755/j01.ms.20.2.5585

Keywords:

micro-solid oxide fuel cell, bulk micromachining, Pt/YSZ/Pt membrane, stress modelling

Abstract

Fabrication process of micro-SOFC membrane structure using the bulk micromachining of silicon technique with SiO₂ and Si₃N₄ sacrificial layers is presented in this study. The process involves back side photolithography, magnetron sputtering of platinum thin films, thermal evaporation of YSZ electrolyte, deep reactive ion etching of silicon, and, finally, release of free-standing membrane using CF₄/O₂ plasma etching.

X-ray analysis shows the cubic phase of YSZ electrolyte and platinum electrodes. Modelling of normal stress distribution in the micro-SOFC structure with the Si₃N₄ sacrificial layer shows that at high temperatures the substrate expands less than the coating, causing tensile stresses in the substrate area next to the coating and compressive stresses in the coating, as the substrate material has a lower coefficient of thermal expansion than the layered Pt/YSZ/Pt coating.

DOI: http://dx.doi.org/10.5755/j01.ms.20.2.5585