Electrowetting on Dielectric (EWOD) Based Portable Multimaterial Printer To Fabricate Origami Devices.

Origami devices are expected to be applied in fields such as space exploration, medicine, and agriculture and are being extensively researched in both scientific and engineering contexts. However, the difficulty of fabrication is high, and it is particularly challenging to fabricate them on-demand and on-site with a compact device. We have a technology for automatically fabricating origami devices by printing conductive and insulating solutions on paper. In this study, we have developed a portable, multimaterial printer using electrowetting on dielectric (EWOD) technique that drives both conductive and insulating liquids. We overcame the low portability of conventional inkjet printers and achieved a palm-sized compact printer. Specifically, we used EWOD to promote the driving of liquid within the channels printed on paper and investigated the electrical input, channel, and electrode designs necessary for proper control. We successfully drove both insulating and conductive liquids and evaluated the printing performance and precision. As a demonstration, we successfully fabricated an origami stretchable strain sensor and a breath sensor using the proposed system and verified the durability of the origami device through repeated testing. The development of a portable control circuit that generates the investigated electrical input signals has enabled the rapid and convenient fabrication of 3D devices without location constraints, potentially accelerating the adoption of IoT devices.