System and method to measure material ductility and toughness using cutting blades

An apparatus for measuring material toughness in a sample using a contact mechanics test, the apparatus comprising:

• a stylus having at least two cutting blades configured to engage with the sample and spaced apart at a distance to define a stretch passage between two adjacent cutting blades, each cutting blade having a blade dive surface and a blade lift surface that intersect to form a cutting edge configured to cut the sample as the stylus travels along a path trajectory, each blade dive surface and blade lift surface has a continuous or discontinuous convex profile along the cutting edge each blade dive surface and blade lift surface configured to contact the sample when cutting the sample;
• and
• a stylus transport system configured to move the stylus along the path trajectory as the at least two cutting blades cut the sample such that the sample is displaced on at least one side of the path trajectory, the stylus configured to separate the sample at or near the cutting edge of each cutting blade when the stylus transport system moves the stylus and configured to form a ligament in the stretch passage when the sample flows between the two adjacent cutting blades and to induce tension in the ligament due to opposing forces of the at least two cutting blades and the sample.