1 Copyright © 20xx by ASME Proceedings of the ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems and ASME 2015 13 th International Conference on Nanochannels, Microchnnels, and Minichannels InterPACKICNMM2015 July 6-9, 2015, San Francisco, California, USA InterPACKICNMM2015-48459 THERMAL STABILITY OF RARE EARTH OXIDE COATED SUPERHYDROPHOBIC MICROSTRUCTURED METALLIC SURFACES Anton Hassebrook University of Nebraska-Lincoln Department of Mechanical and Materials Engineering Lincoln, NE, USA Michael J. Lucis University of Nebraska-Lincoln Department of Mechanical and Materials Engineering Nebraska Center for Materials and Nanoscience (NCMN) Lincoln, NE, USA Jeffrey E. Shield University of Nebraska-Lincoln Department of Mechanical and Materials Engineering Nebraska Center for Materials and Nanoscience (NCMN) Lincoln, NE, USA Craig Zuhlke University of Nebraska-Lincoln Department of Electrical and Computer Engineering Lincoln, NE, USA Troy Anderson University of Nebraska-Lincoln Department of Electrical and Computer Engineering Lincoln, NE, USA Dennis Alexander University of Nebraska-Lincoln Department of Electrical and Computer Engineering Lincoln, NE, USA George Gogos University of Nebraska-Lincoln Department of Mechanical and Materials Engineering Lincoln, NE, USA Sidy Ndao University of Nebraska-Lincoln Department of Mechanical and Materials Engineering Lincoln, NE, USA sndao2@unl.edu ABSTRACT In this paper, we present a method of generating nearly superhydrophobic surfaces from Femtosecond Laser Surface Processed (FLSP) metallic substrates and the study of their thermal stability at high temperatures. Using an FLSP process, hierarchical micro/nano structures were fabricated on stainless steel 316 after which a 200 nm Cerium Oxide (CeO 2 ) film was sputtered onto the surface. Before CeO 2 deposition, the contact angle of sample was measured. Post CeO 2 deposition, the contact angles were measured again. As a result of the cerium oxide deposition, the contact angle of the originally hydrophilic FLSP surface turned near superhydrophobic with an equilibrium contact angle of approximately 140 o . Subsequently, the coated surfaces were annealed in air. The surface maintained its high contact angle from room temperature to about 160 o C, after which it lost its hydrophobicity due to hydrocarbon burn off. For each annealing temperature, we monitored the chemical composition for the cerium oxide- coated FLSP surface using energy dispersive x-ray spectroscopy (EDS) and X-ray diffraction (XRD). Under a nitrogen rich annealing environment, the nearly superhydrophobic FLSP metallic surface maintained its high contact angle up to temperatures as high as 350 o C. To further understand the physics behind the observed phenomenon, we investigated two additional samples of polished stainless steel 310 again coated with 200 nm of CeO 2 .