“…2 The mechanical properties of the zona pellucida and cells, as well as the deformation of egg cells due to mechanical pressure, were studied to assess their hardness. Various methods like indentation, tension, constriction, or vibration 11,[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] were employed to apply mechanical pressure. In some instances, magnetic 29,30 or electrical forces 31,32 were also used to apply or measure mechanical pressure.…”