Determination of damping coefficient of soft tissues using piezoelectric transducer

Measuring viscoelastic properties of soft tissues becomes a new biomarker in the medical diagnosis field. It can help in early diagnosis and related fields, such as minimally-invasive-surgery (MIS) applications and cell mechanics. The current work presents a tactile sensor for measuring the damping coefficient of the soft tissues. The proposed sensor can be miniaturized easily and used in MIS applications. Besides the proposed sensor, a mathematical model, based on Jacobsen's approach, is built to calculate the damping coefficient of the specimens and the surrounding. These damping sources significantly influence the proposed sensor, such as air damping and hysteretic damping. The sensor system principally depends on a piezoelectric transducer, which is cheap, commonly available, and easily integrated into MEMS. To conceptually prove the sensor feasibility, silicon rubber samples with different stiffnesses have been fabricated and tested by the new sensor. The obtained results prove the newly proposed sensor's capability to differentiate the damping coefficients for soft materials effectively.