Table 5.

Comparisons of micro-actuators for medical scanning mirrors.

Actuation type	Advantages	Disadvantages
	Fast response	Pull-in effect
Electrostatic	Low power consumption	High driving voltage
	Large scan angle
	Larger driving force	High power consumption
Electromagnetic	Lower driving voltage	External magnets
	Large scan angle	Electromagnetic interference
	Fast responses	Large initial tilting angle
Piezoelectric	Large bandwidth	Charge leakage problems
	Low power consumption	Hysteresis effect
	Large scan angle	High power consumption
Electrothermal	Low driving voltage	Slow response
	High fill-factor