The use of piezoelectric materials as actuators or sensors is widespread, and numerous actuator topologies and models have been developed. However, many of these applications do not place stringent requirements on actuator mass or energy density. Motivated by applications that do have strict requirements in these areas such as flapping-wing microrobots, a torsional piezoelectric actuator is developed. A model is presented that predicts output rotation, torque and energy density values; and allows optimization of these values based on actuator geometry. An emphasis is placed on actuator fabrication and testing for empirical validation of the model.