CircWood: Laser Printed Circuit Boards and Sensors for Affordable DIY Woodworking

Due to its natural warmth, wood is frequently used to produce touchable objects such as furniture and signboards. Laser cutting machines are becoming common in personal wood processing to cut and engrave wood. In this paper, we propose a method and workflow for producing various sensors and electrical circuits for interactive devices by partially carbonizing the wood surface with a laser cutting machine. Similar to wiring on a conventional printed circuit board (PCB), the carbonized part functions as a conductive electrical path. A method for creating electronic circuits and sensors made of carbon graphene on botanical materials has been proposed. This technique makes use of a raster-scanning femtosecond (fs) laser, which is less common for personal fabrication than a constant-wave (CW) laser. Moreover, raster-scanning requires a substantial amount of time to create a circuit that is mainly made of conductive lines. This paper extends the method with a defocused vector-scanning CW laser beam and reduces the time and cost required for fabrication. The proposed method uses an affordable CW laser cutter to fabricate an electrical circuit, including touch sensors, damage sensors, and load sensors on wood boards. The circuit can be easily connected to traditional PCBs and electric parts such as one-board microcomputers using metal screws and nails typically used in DIY woodworking. We develop ease of use software design tool that supports the creation and fabrication of carbon paths. In addition, we report on a series of investigations, including optimizing wood materials and laser parameters to establish design guidelines.