So, how are you hoping to improve a bike lock, w/o making it intolerably slow to use, heavy or inflexible?
If someone really wants your bike, a battery operated angle grinder will go through any U-lock in 15-30 seconds.
Thinner stuff, in the time it takes to fit the bolt cutters and heave.
Developing or finding a strong material for a bike lock is a very difficult challenge. Bicycle thieves, are experts in breaking different kinds of locks. But, there is a possible way to prevent that, and that is a big challenge for you. I suggest you focus first in developing a strong material for your bike lock, or perhaps use high carbon, high molybdenum steel or something even more tougher material. Good-luck! I hope this helps.