Evolving Physical Creatures

One of the prevailing characteristics of natural life is autonomy. The field of Artificial Life has so far addressed the notion of autonomy mostly in terms of power and behavior. In this paper we attempt to extend the notion of autonomy to include also design and fabrication: We claim that not only should artificial creatures be able to operate untethered and without external guidance, but they should also he, like living systems, autonomously designed and fabricated without external intervention. Only then can we expect synthetic creatures to bootstrap and sustain their own evolution. In this work we demonstrate for the first time a path that allows transfer of virtual diversity into reality, and so reduce this key principle of Artificial Life into practice. Our approach is the use of only elementary building blocks in both the design and embodiment. We describe a set of preliminary experiments evolving electromechanical systems composed of thermoplastic, linear actuators and neurons for the task of locomotion, first in simulation then in reality. Using 3D solid printing, these creatures then replicate automatically into reality where they faithfully reproduce the performance of their virtual ancestors.