Cell stiffness measurement using two-fingered micro-hand equipped with plate-shaped end effector

In the field of life science which includes, for example tissue engineering and cloning, the manipulation and analysis of cells is important. However, manipulating micro objects by hand without the help of equipment is a difficult task. We developed a two-fingered micro-hand, which can help to operation of micro objects and increase operation efficiency. The cell´s stiffness is an important mechanical property for the understanding of the cell´s condition. Kawakami and others have developed a technique to measure cell stiffness using a two-fingered micro-hand with needle-shaped end effectors. This paper proposes a method to measure the stiffness of softer cells using plate-shaped end effectors. By using a plate-shaped end effector, in the process of cell deformation, the reaction force from the cell will increase more than when using needle-shaped end effectors. Thus, it is possible to measure the stiffness of softer cells. We calculate it by using the values from the micro force sensor and the displacement calculated from the images obtained during the process of deformation. In this paper, we propose a model of a plate-shaped end effector and a stiffness measurement method suitable for the new end effector, and compare the experimental results of our model and the needle-shaped model.