Soft Tissue Elastic Modulus Measurement and Tumor Detection Using Piezoelectric Fingers

We have investigated probing breast tumor in a lumpectomy sample using a newly developed piezoelectric finger (PEF). PEF is a piezoelectric cantilever that consists of a top driving piezoelectric lead zirconate titanate (PZT) layer and a bottom sensing PZT layer sandwiched to a middle stainless steel layer. A PEF can both apply a force and detect the corresponding displacement in one single device by simple electrical means. Applying an electric field to the driving PZT layer causes the PEF to bend which in turn causes a measurable induced voltage across the sensing PZT layer that is proportional to the deflection of the PEF’s tip. Earlier studies have demonstrated that with the appropriate tip geometry, the PEF could accurately measure the elastic and shear moduli of a soft material. It could also differentiate and locate hard inclusions embedded in a soft matrix by the contrast of elastic moduli. In this study, we applied the PEF to probe a lumpectomy sample and located the tumor inside the sample using the spatial contrast of elastic moduli.