Design, modeling and control of a piezoelectric ultrasonic microdissection technique for themolecular analysis of tissue

Abstract

Molecular techniques are transforming our understanding of cellular function and disease.However, accurate molecular analysis methods will be limited if the input DNA, RNAor protein is not derived from a pure population of cells or is contaminated bythe wrong cells. The modeling and control of the piezoelectric actuator, with anobjective application towards ultrasonic vibration cutting (UVC), is addressed inthis paper. The piezoelectric actuator is used in realizing the fast and precisemovements of the developed UVC so as to procure a pure population of targeted cellsfrom tissue sections for subsequent pathology analysis with precision and withoutcausing a large deformation. To address the nonlinearities and uncertainties ofthe piezoelectric actuator, an adaptive controller based on a hysteresis model isproposed to yield robust control performance. A multilayer piezoelectric actuator isused to actuate a sharp needle vibrating at high frequency and low amplitude tocut the tissue. Experimental results showed that the embedded tissue can bequickly and precisely cut with this ultrasonic vibration microdissection method.