Aigen's solar-powered autonomous robots aim to take the chemicals and toil out of industrial weeding. Oblivious to the punishing midday heat, a wheeled robot powered by the sun and infused with artificial intelligence carefully combs a cotton field in California, plucking out weeds. As farms across the United States face a shortage of laborers and weeds grow resistant to herbicides, startup Aigen says its robotic solution—named Element—can save farmers mon