Kaiyi Jiang grew up in a family of doctors in China and saw the limits of the profession. No matter what the physicians in his family tried, sometimes their patients remained sick. So rather than go into medicine, he started thinking about how to design better drugs. Now at Princeton University, Jiang hopes to use artificial intelligence to help answer a fundamental question in drug design: How do you get the right treatment to the right place in the body and have it work at the right time? His.