Dutch designer Joris Laarman has created a 3D-printing robot that can draw intricate metal structures on almost any surface. The MX3D-Metal is part printer, part welder, with a robotic arm that melts and sculpts a variety of metals, including steel, stainless steel, aluminum, bronze and copper, into freestanding designs. Different types of 3D lines, like straight, curved or spiral, require different…