In most of my clothes and luggage that have zippers, the zipper is the first component to fail. There is need for zipper design improvement. The zipper is a mature product. Design improvement may be impossible.

There are 2 sources of zipper failure, one in the slider and one in the teeth.

Slider failure occurs when the crosspiece between the inside and outside parts of the slider, bends. The inside and outside parts of the slider separate slightly. The teeth are not forced together sufficiently to make them interlock completely. A sturdy U-shaped cover over the slider, attached after the rest of the zipper is assembled, and glued to both the inside and outside parts of the slider, would prevent bending and separation of the slider.

Tooth failure occurs when meshed teeth separate spontaneously. Look carefully at the Wikipedia diagram of the teeth. It appears that the teeth do not mesh smoothly. That may be fact, or it may be a deficiency of the diagram. In the mid-20th century there was mathematical derivation of the optimal curve for meshing of gear teeth. I think the derivation also would apply to meshing of zipper teeth. Investigation needed.

http://en.wikipedia.org/wiki/Zipper

3D printer would be used for experimentation and prototyping, maybe on a scaled-up model.