Microengineering is the work of designing and making structures and machines that are extremely small — so small you often need a microscope to see the moving parts. Think of tiny gears, pumps, sensors, or switches that sit on a chip, or tools that work at the scale of a human hair or smaller. Engineers use it when they want something that is light, cheap to copy many times, and able to sit inside a phone, a medical device, or a piece of lab equipment. Though actually, people mix this up with nanotechnology: nano is even smaller (atoms and molecules). Microengineering usually lives one step up, at the scale of millionths of a metre. It is a technical word. You will meet it in science, factories, and university labs, not in everyday chat. It names the activity — the designing and building — more than one single object.