In various embodiments, a phacoemulsification tip may include a shaft and a cutting edge portion having at least a first and second bend, wherein the at least the first and second bends (102,104) are positioned such that the ultrasonic torsional vibration energy in the tip (100) during ultrasonic torsional vibration is in a twisting vibrational mode along a substantial portion of the shaft (108). The geometry of the tip may be configured to result in a lateral displacement ( u x ), perpendicular to the shaft during torsional vibration of the tip at frequencies between 10 kHz and 60 kHz, of less than approximately 5% to 25% (e.g., 15%) of the lateral displacement at the distal end point of the tip throughout a portion of the shaft extending from the end of a conical portion of the tip through to the first bend in the cutting edge portion of the tip. Software and/or physical modeling may be used to determine the tip geometry.
