New MEMS tweezers for the viscoelastic characterization of soft materials at the microscale

01 Pubblicazione su rivista
Di Giamberardino Paolo, Bagolini Alvise, Bellutti Pierluigi, Rudas Imre J, Verotti Matteo, Botta Fabio, Belfiore Nicola P
ISSN: 2072-666X

As many studies show, there is a relation between the tissue's mechanical characteristics and some specific diseases. Knowing this relationship would help early diagnosis or microsurgery. In this paper, a new method for measuring the viscoelastic properties of soft materials at the microscale is proposed. This approach is based on the adoption of a microsystem whose mechanical structure can be reduced to a compliant four bar linkage where the connecting rod is substituted by the tissue sample. A procedure to identify both stiffness and damping coefficients of the tissue is then applied to the developed hardware. Particularly, stiffness is calculated solving the static equations of the mechanism in a desired configuration, while the damping coefficient is inferred from the dynamic equations, which are written under the hypothesis that the sample tissue is excited by a variable compression force characterized by a suitable wave form. The whole procedure is implemented by making use of a control system.

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