Microwave drill for ceramics

The paper introduces a method for drilling into hard non-conductive materials by localized microwave radiation (US patent 6,114,676). The microwave drill utilizes a conventional microwave source (2.45-GHz magnetron) to form a portable and relatively simple drilling tool. The drilling head consists of a coaxial feed with a near-field concentrator. The latter focuses the microwave radiation into a small volume under the drilled-material surface. The concentrator itself penetrates into the hot spot created in a fast thermal runaway process. The drilling debris is removed mechanically. This microwave device can be used to drill into concrete, silicon, ceramic, rocks, glass, plastic, and even wood. Hole diameters obtained so far range from 0.5 mm to 13 mm. The larger holes are produced with a slight mechanical assistance. The paper presents recent experimental results of the microwave-drill in various ceramics.