Animatronics is a multi-disciplinary subject that embraces both art and. science It is acknowledged as a new discipline" and attracts a wide audience; In academia and discussion terms, this creates a problem as to where to place the subject, and how to define its key principles. This thesis sets out to investigate the practice and principles of animatronics design; to discover where it came from, what it encompasses and how it might develop. Early research establishes the definition of animatronics, which is developed by empirical research from industry. The structure and working practice of a major animatronics studio in the UK, Creature Shop, were examined and followed by an in-depth case study of the making of models for the BBC's 'Walking with Dinosaurs' production. The principles arising from the investigation have been tested by project, and the project brief was to make an animatronics model to explore the best methods for reproducing the correct facial movements to express fear, anger, sorrow, happiness, disgust and surprise. In this project the mouth and lip area was selected for the experiment, and both an art and engineering methodology were used and the results recorded. The value of the investigation is the platform it provides for process and practice, and the understanding this offers as a base line from which to move forward. It also presented an opportunity for the author to contribute to the animatronics design studio's working methods in a way that it acknowledged and is currently still using. The working title of the new role created was The Bridge, and the method used is a graphical movement design and navigation board. The thesis defines animatronics as an independent, interdisciplinary subject that draws diverse professionals together through its creative approach and its emphasis on visual communication methods. Because of the element of surprise or wonder that surrounds the technology, its future will rely on dramatic performance and the interactive area of artificial intelligence. Animatronics models require the 'wow factor' to maintain the public's interest, or to grow closer to new applications in biomechanics, robotics and amphibiotics.