To be completely honest you've given absolutely no useful information in this post to enable anyone to answer you with any measure of accuracy. I'm not certain that you can either, at least not without revealing the product of your mad scientist type aspirations.
What you are asking requires specific calculations based on principles of Physics, Chemistry, Calculus, and Algebra (possibly Trigonometry also since I'm not sure what you're looking for). If you plan on conquering these yourself you should at least be quite proficient in Calculus and have some background in Calculus based Physics.
Can you offer any details at all? What measure of energy is required to perform the work you seek? Is there a distance that needs to be observed? Is there a specific velocity that needs to be achieved, or a measurable pressure that needs to be applied by this spring? Is it a question of angular velocity like a mouse trap? Are you familiar with Hooke's law? Are you just looking for a spring constant so you can calculate the potential of different materials?
The more I ponder your question, the more confused I am. Anyone attempting to tackle a problem of this magnitude should at least know what's involved in finding the answer, and be ready to offer the necessary variables.
At this point, anything you can offer would be more than you have, because considering what you've furnished I can only suggest trial and error.