For example: Werner Forssmann
It seems nothing and no one could stop Werner Forssmann from sticking a rubber tube into an artery in his arm and pushing it all the way into his heart.He did it - over lots of objections - and paved the way for arterial catheter treatment of blocked arteries. He won a Nobel Prize in 1956.
On the use of drugs in research, Kary Mullis used LSD (and other hallucinogens after LSD became illegal) to aid in his thinking about DNA.
Thanks to the psychedelic input, Mullis said he could imagine himself "down there with the molecules", looking at what would need to happen in order for the DNA strands to separate and be copied. He almost certainly wouldn't have had his breakthrough idea without the aid of the drugs, he admitted.He won a Nobel Prize in 1993.
And my favorite real “Mad Scientist,” Nikola Tesla.
Tesla was the ultimate eccentric genius, best exemplified by his hallucinatory vision of the self-starting electric motor. One afternoon in 1881, he and his friends were in Budapest Park, walking towards the setting sun. Tesla was reciting a few lines of Goethe's poetry when he suddenly went catatonic, staring at the sky. There, he said, he could see a fiery magnetic field being made to rotate by a ring of electromagnets, inside which was a hulk of iron. He blurted out, "See my motor here... watch me reverse it," at which point his friends grabbed him and shook him until he returned to normal (normal for Tesla, at least). Tesla went back to his laboratory and built what he had seen - what is now known as the self-starting alternating current motor. It worked first time.There is more about others as well.