Ultrasonic cutting with a d31-mode PMN-PT-driven planar tool

Ultrasonic cutting tools based on a mass-spring configuration of a drive transducer are widely used in surgery. However, the weight and self-heating of this configuration are weaknesses. An alternative approach is to use a planar tool to which piezoelectric drive components are bonded directly. This paper details the design and characterization of such a tool, utilizing PMN-PT relaxor single crystal material operated in the d(31) mode. The tool, resembling a dagger, is able to produce longitudinal displacements > 6 mu m when driven with 50 Vp-p at the resonance frequency, 73 kHz. The effectiveness of finite element analysis has been observed as the behavior of the tool was accurately predicted prior to its fabrication. Furthermore, ways to improve the efficiency of the tool by reconfiguring the material have been explored and implemented.