Slicing of a soft solid

Meng Li; Preetika Karnal; Yinan Lu; Chung-Yuen Hui; Anand Jagota

doi:10.1063/5.0160570

Slicing of a soft solid

J Chem Phys. 2023 Sep 21;159(11):114704. doi: 10.1063/5.0160570.

Authors

Meng Li¹, Preetika Karnal¹, Yinan Lu¹, Chung-Yuen Hui^{2

3}, Anand Jagota^{1

4}

Affiliations

¹ Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
² Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853, USA.
³ Soft Matter GI-CoRE, Hokkaido University, Sapporo 001-0021, Japan.
⁴ Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, USA.

PMID: 37725659
DOI: 10.1063/5.0160570

Abstract

Cutting of soft materials is a complex problem, which is still not well understood at the fundamental level, especially for soft materials. The cutting process we consider is slicing, which starts with indentation, followed by sliding of a knife on the material to be cut. Here, we describe cutting experiments on PDMS elastomers with three different moduli. Our experiments reveal typical stages of this cutting process, starting with indentation and ending at steady state cutting. The process starts with a pre-cutting phase in which the blade does not slip grossly relative to the solid to be cut, and deformation is mostly elastic. Slip of the blade initiates suddenly and is often accompanied by initiation of cutting. Cutting is relatively smooth in the next stage, which requires a continuous increase in shear force. For soft PDMS, this smooth cutting stage is followed by one in which folds or creases form on the cutting surface. The corresponding shear force response is no longer smooth as "steady" sliding occurs in a stick-slip fashion with oscillatory forces. The average shear force reaches a plateau and no longer increases with shear displacement. Experimental observations of the various cutting stages are interpreted quantitatively.