ABSTRACT
Actuators are devices that perform mechanical work in response to a command or control signal. The
device can be separated into two parts: the actuator shell and the method of actuation. The shell is the
basic structure of the actuator and, often, contains deformable or moving parts. Pneumatic cylinders
and mechanical linkages are large-scale actuator shells. Examples of deformable microactuator shells
include cantilever beams, microbridges, diaphragms, and torsional mirrors [1]. The main function of any
shell design is to provide a mechanism for the desired actuation method to produce useful work. The
actuation method is the means by which a control signal is converted to a force that is applied to the
actuator shell and creates physical movement. The output of the overall system is the desired response
given as a displacement, force, or pressure value. The different methods of actuation take advantage of
mechanical, electrostatic, piezoelectric, magnetic, thermal, fluidic, acoustic, chemical, biological, or
optical principles.
