Continuous Process for Large-area Flexible MEMS

A novel fabrication Process for large area flexible MEMS, having been developed in BEANS project, Japan, is introduced. The process consists of continuously high-speed coating for functional film materials, 3-D nano/micro-machining of the films on fibers, and weaving the functional fibers into large-area integration. In the coating process, functional materials, e.g., organic semiconductor, piezoelectric, conductor and insulator films could be formed on fibers with a speed of 20 m/min. In the 3-D nano/micro-machining, a compound reel-to-reel process system including both thermal roller imprint and photolithography functions was developed. In addition, the microfabrication of the 3-D exposure module and the spray deposition of thin resist films on the fibers were demonstrated. For the weaving assembly, a round-projection microspring contact structure was developed for the electrical contact between weft and warp fibers in a large area of woven textile. Evaluation of the durability showed that the microspring contact structures made of silicon elastomer and PEDOT:PSS are applicable to a movable contact. Weaving assembly process was verified by prototyping 1 x 1 m(2) or larger flexible touch sensor sheets using functional fibers with organic insulating/conductive films.