Rubber friction directional asymmetry A. Tiwari, L. Dorogin, B. Steenwyk, A. Warhadpande, M. Motamedi, G. Fortunato, V. Ciaravola and B. N. J. Persson EPL, 116 6 (2016) 66002 Published online: 08 February 2017 DOI: 10.1209/0295-5075/116/66002