Distraction osteogenesis is a method of generating new bone formation by the gradual application of tensile stress across an osteotomy site (a complete cut through the bone). Internal or intraoral distraction devices have become the most common clinical apparatus in craniofacial distraction osteogenesis, although actuating the distraction devices relies upon manual length adjustment under patients’ compliance, introducing inconvenience and potential error in the procedure. To realize a fully implantable automatic distraction device, we propose a device design comprising a continuous miniature motor-driven distractor with a controller and an on-board lithium-ion battery. A benchtop prototype was fabricated to demonstrate the device’s structural design capable of transmitting sufficient loads with sufficient strain accuracy; it is capable of using a battery selection algorithm to determine an appropriate electrochemistry, temperature, sealability, and form factor and a control algorithm and a testing protocol with a laboratory-fabricated control circuit. This new distraction osteogenesis device enables completely automated and continuous distraction by the application of a low strain magnitude with multiple steps potentially leading to enhanced osteogenic activity.