A haptic alert system generally includes an active material based actuator
for providing the haptic alert. The active material based actuators refer
to the use of several different classes of active materials all of which
exhibit a change in at least one attribute such as dimension, shape,
and/or flexural modulus when subjected to at least one of many different
types of applied activation signals, examples of such signals being
thermal, electrical, magnetic, stress, and the like.