A precision dimple grinder-polisher produced by 3D printing

A precision dimple grinder-polisher has been designed and constructed using 3D printing. The purpose of the device is to produce a thin central area in 3 mm round samples for transmission electron microscopy before ion milling to electron transparency. The device can be self-made by any laboratory with a 3D printer for scientific research or teaching, and when combined with recycling and use of biodegradable filaments it can help labs reach their sustainable development goals. A novel sample holder design allows sample alignment without a monocular and thickness detection by light transmission. Novel solutions are developed for aligning the grinding disc and sample rotation motors and for fixing the polishing cloth to the polishing disc. The diameter-depth relationship is investigated for steel and plastic grinding discs. Design principles and materials are discussed, and the tool is evaluated by preparing samples from copper, silicon and tungsten, which are then examined in the transmission electron microscope to evaluate their quality.