Characterization and modeling of frog gastrocnemius muscles under electrical stimulation

Actuator development is a popular research topic due to big demand for more efficient, light and small actuators. Present thesis is part of a TÜBİTAK research project to develop a vehicle that uses a live muscle as an actuator. The thesis aims to characterize and measure mechanical performance of frog gastrocnemius muscles. The contractile properties of muscles are tested by means of a test system developed previously by another graduate student in the Mechanical Engineering Department of Yeditepe University. The existing experimental setup is used for in vitro electrical stimulation of muscles. Twitch response of isolated muscles is measured in vitro at different muscle lengths for different voltages, frequencies and pulse widths. Tetanic and fatigue experiments are carried out on a statistically adequate number of muscles. An existing phenomenological mathematical model for twitch response is improved and a fatigue model is developed. Mathematical models are fitted to experimental results. Frogs used in the experiments are purchased from frog farms and used in accordance with animal ethic rules approved by the Ethics Committee of the University.