I've recently stumbled upon David Eagleman's TED talk on the concept of sensory substitution and addition. Being the most inspiring thing I've seen on the internet for the last few months I've decided to give it a try and mix it with some of my coding/electronics projects.
I've settled on using electrical impulses over electrode pads to feed sensory data onto a patch of skin, instead of vibro-motors as it is more energy efficient. That being said, when planning on running electrical current through me 24/7, safety obviously comes first.
I am targeting the lower back or the side of the hips as these parts have the least contact with the environment and won't make you look goofy. In the long run this would probably have to run on dry skin to avoid the "wrinkling effect", caused when staying in water for too long.
Main unknowns I want to sort out are:
What is the range of perceivable voltage and current that can be safely fed through the skin without causing any damage to the nerves or any other part of the body?
Is there a risk of permanent damage or reduction of sensitivity of nerves when exposed to an electrical current for a prolonged time? Any way to circumvent this problem?
What "resolution" or input density can I hope to achieve, before signal becomes "blurry" because of cross-talk?