Cone cracks in tissue-mimicking hydrogels during hypodermic needle insertion: the role of water content

Abstract

Needle insertion into soft biological tissues is a common process in various surgical procedures. During insertion, soft biological tissues with different water content undergo large deformation often leading to uncontrollable...

Force decomposition and toughness estimation from puncture experiments in soft solids

“…35 Additionally, needle insertion into soft solids can also create complex crack geometries such as cone cracks, for both blunt needles 34 and sharp-tipped needles like hypodermic needles. 36 Based on quantification of the deformation field in a soft solid, compression is mainly observed below the tip of a blunttipped cylindrical indenter, while shear is mostly observed on the sides of the indenter. 22 The bulk resistance of the soft solid to puncture initiation arises from the shearing zone on the sides of the indenter, rather than the compression zone below the indenter tip.…”

“…35 Additionally, needle insertion into soft solids can also create complex crack geometries such as cone cracks, for both blunt needles 34 and sharp-tipped needles like hypodermic needles. 36…”