Bone Cutting Performance of Ultrasonic Surgical Tools Incorporating PZT Piezoceramic and Mn:PINPMN-PT piezocrystal

Bolted Langevin-style Transducers (BLT) are widely adopted in ultrasonic surgical devices. A BLT is normally comprised of a stack of piezoelectric Pb(Zrx Ti 1 -x)O 3 (PZT) rings. Recently, piezoelectric single crystal material Mn-doped Pb(In 1/2 Nb 1/2 )O 3 - Pb(Mg 1/3 Nb 2/3 )O 3 - PbTiO 3 (Mn:PIN-PMN-PT) has emerged as a potential alternative, as it simultaneously exhibits high piezoelectric coefficient, dij, electromechanical coupling coefficient, kij, and mechanical quality factor, Qm. A stepped shape horn with a thin and rounded blade is attached to two BLTs, one incorporating piezoceramic and one incorporating piezocrystal material. The full devices were tuned to L2 at 20 kHz. Ex-vivo tissue cutting experimental results show that the Mn:PIN-PMN-PT driven surgical device has consumed more power and has successfully penetrated through the bone. However, the impedance matched PZT device has lost stability as the penetration progressed. This distinction is ascribed to the higher power density of the piezocrystal material