Cellular muscle actuators with variable resonant frequencies

This paper presents the design and analysis of a novel variable stiffness and variable resonance actuator based on a cellular arrangement of piezoelectric devices. The cellular muscle actuator design concept is presented followed by a general dynamic model for establishing the theoretical bounds on achievable resonant frequencies. A model that is specific to the proposed design is then formulated to include the effects of parasitic dynamics. The resonance characteristics of a three cell prototype system are identified experimentally. The theoretical model and experimental results agree over a large frequency range and illustrate the variable resonance concept.