Fluidity and grace have not been among words frequently used to describe the movements of robots. But technological advances are enabling humanoid robots to do some complex and funky dance choreography. Fulton Schools Assistant Professor Heni Ben Amor says four robots made by an engineering and robotics design spin-off from the Massachusetts Institute of Technology foreshadow a future in which robots that are human in size and shape are capable of mimicking intricate and rhythmic human motions. Amor, an expert in human-robot interactions and machine learning, predicts the day will come when humans and robots team up to give ballet performances.