Table 4 Cutting by pressing and sliding: lessons from cheese and salami slicing

Cutting of soft materials, be it human flesh by the surgeon, meat or vegetables by the chef, or tissue samples by the histologists, is made considerably easier by sliding the blade rather than just pressing it against the surface of the object to be cut. This principle also holds for the common “paper cut”, the painful rendezvous between the skin and a thin paper sheet. The phenomenon has been modelled with a wide variety of materials, and different explanations have been provided. Atkins and colleagues [101] lively review the mechanics of cutting and define our study object as a material in which sectioning creates a floppy offcut that is not permanently deformed and has negligible bending resistance. These authors demonstrate (by cutting cheddar cheese and salami) that the greater the “slice/push ration”, the lower the necessary cutting forces. Reyssat and colleagues [102] focus on the role played by shear forces on gelatin blocks and reveal that the sliding action creates a critical local tension at the contact site, in contrast to a strong global tension caused by pressing only. Thus, under slicing (= blade vibration) conditions, there is less global deformation and material damage, resulting in better preserved slices – in our context the key motivation for employing vibrational cutting