Make an Origami Circuit Board

Researchers at the City University of Hong Kong have developed a method for creating conductive paper by combining a liquid metal alloy with traditional papercraft techniques, eliminating the need for molds to form electrical traces. The team from the School of Creative Media’s MEI Lab used a gallium-indium liquid metal to impregnate a paper-like nonwoven textile. Applying pressure through folding or cutting cracks an insulating oxide layer on the microscopic metal droplets, merging them to create conductive paths [1]. The process draws on origami and kirigami, crafts that use folding and cutting to shape paper [1]. The researchers modified the fabrication method by using an airbrush to spray a mixture of isopropanol and liquid metal onto the substrate, allowing them to control deposition and use stencils to keep certain areas non-conductive [1]. Testing showed that the pressures from folding and cutting, which range from 2.5 to 100 megapascals, are sufficient to form reliable traces [1]. The resistance measured 23.18 ohms per centimeter for cut edges and 4.4 Ω/cm for folded edges, with conductivity remaining stable even if folds are later flattened [1]. The material cost for a 10- by 10-centimeter piece is approximately US $1.80 [1]. To make the technique accessible, the researchers built a toolkit called LiqMetCraft. It includes the necessary materials and a browser-based software tool that guides users through design and construction [1]. The toolkit was tested in three versions: a Chinese papercraft style with radial symmetry, an origami version with 12 folding templates, and a 3D paper model-making version that supports a cutting machine [1]. A study with 42 participants found the system easy to use, with some users moving beyond the supplied designs to create their own [1]. The work was presented at CHI ’26, the 2026 Conference on Human Factors in Computing Systems [1]. The researchers plan to explore different substrates and additional papercraft forms, such as pop-up books, and to develop ways to build interactive inputs like switches and potentiometers directly from the material [1].