laser

Carbon Robotics has created an autonomous laserweeder – a ~10,000 lbs. self-driving robot that can kill 100,000 weeds an hour using eight 150-watt lasers. – WTF Fun Facts

Source: Self-Driving Farm Robot Uses Lasers To Kill 100,000 Weeds An Hour, Saving Land And Farmers From Toxic Herbicides (forbes.com)