We've just posted step-by-step instructions and a demo video on how to build your own muscle (EMG) sensors compatible with Arduino microcontrollers. Use it to control video games, robot arms, etc.
Snippet of the intro...
"Measuring muscle activation via electric potential, referred to as electromyography (EMG) , has traditionally been used for medical research and diagnosis of neuromuscular disorders. However, with the advent of ever shrinking yet more powerful microcontrollers and integrated circuits, EMG sensors have found their way into prosthetics, robotics and other control systems. Yet, EMG systems remain expensive and mostly outside the grasp of modern hobbyist."
Hope you find the instructions useful. Don't hesitate to let us know if you have any questions of need any help building a sensor for your next project!