%0 Journal Article %T Cutting and Slicing Weak Solids %+ Physique et Mécanique des Milieux Divisés (PMMD) %+ Laboratoire d'hydrodynamique (LadHyX) %A Mora, Serge %A Pomeau, Yves %< avec comité de lecture %@ 0031-9007 %J Physical Review Letters %I American Physical Society %V 125 %N 3 %8 2020-07-15 %D 2020 %R 10.1103/PhysRevLett.125.038002 %Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] %Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph]Journal articles %X Dicing soft solids with a sharp knife is quicker and smoother if the blade is sliding rapidly parallel to its edge in addition to the normal squeezing motion. We explain this common observation with a consistent theory suited for soft gels and departing from the standard theories of elastic fracture mechanics relied on for a century. The gel is assumed to fail locally when submitted to stresses exceeding a threshold σ 1. The changes in its structure generate a liquid layer coating the blade and transmitting the stress through viscous forces. The driving parameters are the ratio U=W of the normal to the tangential velocity of the blade, and the characteristic length ηW=σ 1 , with η the viscosity of the liquid layer. The existence of a maximal value of U=W for a steady regime explains the crucial role of the tangential velocity for slicing biological and other soft materials. %G English %2 https://hal.science/hal-02925886/document %2 https://hal.science/hal-02925886/file/Mora_Pomeau_PRL_2020.pdf %L hal-02925886 %U https://hal.science/hal-02925886 %~ X %~ CNRS %~ LMGC %~ X-LADHYX %~ X-DEP %~ X-DEP-MECA %~ MIPS %~ UNIV-MONTPELLIER %~ IP_PARIS %~ UM-2015-2021