In this project the PI will develop a neuromechanics of locomotion on dry and wet granular substrates. This will be used to address how effective movement results from the interaction of body morphology and posture, muscles, Central Pattern Generators (CPG), and sensory systems with the physical features of complex environments like solidification and fluidization. The PI will study three organisms -- sandfish lizards, zebratailed lizards, and salamanders -- that respectively swim, walk and run effectively within and on granular substrates. These organisms will be chosen as representatives of effective locomotion in a given substrate: the sandfish swimming in sand, the zebra-tailed lizard sprinting over a diversity of granular terrain, the salamander walking in mud. The salamander also embodies features thought to be representative of early tetrapods. The project will use high speed imaging (both visible light and x-ray), granular force platforms, and electromyography (EMG) to record kinematics, dynamics, and muscle activity. The PI will develop controlled granular substrates using fluidized beds which will allow both creation of repeatable initial conditions and rapid perturbations to generate neuromechanical control hypotheses. Robotic models of organisms to test hypotheses will be built as well. The models will have relevance to organisms in the present and will be a step toward development of quantitative hypotheses of the evolution of movement on land. Understanding of the physics of soft materials like mud and wet sand will be enhanced. The work also has clear implications for robotics; in the modern world, in which disasters are common and affect many lives, there is a pressing need for devices that can explore complex shifting terrain. The PI will use the robots from the locomotion research to create hands-on robot modules to teach science by: 1) Developing and teaching a course in hands-on experimental science for undergraduates emphasizing principles of mechanics, electronics and biology. 2) Bringing K-12 teachers to Georgia Tech in the summer to learn to use hands-on locomoting robot kits. 3) Developing "Robotics Inspired Science Education" (RISE) nights to utilize robots to generate interest and teach principles of science to the public.
