Guitar strings make great micro springs, whether you use them straight, or coil them. the thicker(wound) strings work great for a straight perfectly bendable micro spring. If you decide to wind your own, use a medium guage wire(Not wound) and coil it around any object smaller in diameter. applying a little heat also helps just don't let it turn red hot to the point where the wire gets deformed.
This is probally the only original idea i've had and thought i'd share
