SIGMO's design is based on passive-dynamic technology, allowing it to achieve human- like locomotion without using motors. This is possible by using an accurate mechanical structure which resembles the human skeleton. The legs (hips, knees, ankles) are the only portion of the design based on passive-dynamic technology, as the upper body utilizes motors for movement.

A way to look at the passive-dynamic approach is to imagine a human body. A muscular system with no skeleton is simply a mass of tissue and impulses. The passive-dynamic approach tells us to use a different perspective- what can a skeleton do without muscles? Surprisingly enough, the skeleton can still achieve locomotion. This serves as the basis for SIGMO's design and the reasoning behind the technology used.

Support for Voice Activated Commands was added on August 8th, 2005. This was a major building block for the SIGMO robot as it was the main interface for human interactivity. We had hoped to add a higher number of interactive features, but due to time and money constraints our goals proved improbable for the current time frame. However, without the addition of the voice-command control interface, SIGMO would not have been nearly as interactive or been able to achieve even the most basic level of "humanoid" we were aiming for.

Fortunately the era we live in is very advanced, with new technologies popping up everyday. I had ideas of basic Artificial Intelligence I wanted SIGMO to incorporate, and found new and better ideas as I searched for solutions. A list of things I wanted SIGMO to accomplish provided our budget allowed it:

• Facial Recognition
• Facial Gesture Estimation and Tracking
• Hand Gesture Recognition
• Hand Tracking
• Posture Recognition and Tracking
• Speech Recognition
• Response Database with Rapid Compiler
• Speech Synthesis with Facial Animation
• Voice Command Technology

These technologies were very advanced, but were becoming less expensive to implement as time went on. Time is always a major issue in R&D, as even though outsiders see the line as "month's away," you must keep in mind roadblocks, such as software/ hardware in compatibilities, funding problems, or fabrication redesign. For these reasons all hardware and software was to be purchased or acquired as soon as possible, to exploit all possible variations and learn the most efficient method of control.