Hiten Dharpure, a 17-year-old boy from India's Nagpur, has set a Guinness World Record for the smallest robot arm, measuring 39.25 mm (or 1.54 inches). The robot arm can grip and lift small objects with precision, despite its size. Dharpure reportedly used FDM-based 3D printing technology to construct the robot arm, which features a 3-axis motion path.