Effect of substrate roughness on the apparent surface free energy...
Effect of substrate roughness on the apparent surface free energy of sputter deposited superhydrophobic PTFE thin films, H. C. Barshilia, D. Krishna Mohan, N. Selvakumar, K. S. Rajam, Applied Physics Letters, 95 (2009) 033116, doi: 10.1063/1.3186079