Patent ID: 8882791

Claim:
A surgical instrument, comprising: a transducer configured to produce vibrations at a predetermined frequency; and an ultrasonic blade extending along a longitudinal axis coupled to the transducer, wherein the ultrasonic blade comprises: a substantially solid, substantially cylindrical body without a channel formed from a first metallic electrically conductive material, the body having a proximal end and a distal end, wherein the distal end is movable relative to the longitudinal axis by the vibrations produced by the transducer; at least one annular layer of a second metallic electrically conductive material formed on at least a first portion of the body, the second metallic material being suitable to carry an electric charge from a direct current electrical source, wherein the first metallic material is different than the second metallic material; and at least one annular layer of a third electrically insulative material formed on at least a second portion of the body, wherein the third electrically insulative material is located intermediate the first metallic material and the second metallic material, wherein the third electrically insulative material is different than the second metallic material, wherein the third electrically insulative material comprises an electret material, and wherein the third electrically insulative material entirely encloses the first metallic material to electrically isolate the first metallic material from the second metallic material.