AVS 56th International Symposium & Exhibition
    MEMS and NEMS Thursday Sessions
       Session MN-ThP

Paper MN-ThP1
Imprinting of Guide Structures to Weave Nylon Fibers

Thursday, November 12, 2009, 6:00 pm, Room Hall 3

Session: MEMS and NEMS Poster Session
Presenter: H. Mekaru, AIST, Japan
Authors: H. Mekaru, AIST, Japan
M. Takahashi, AIST, Japan
Correspondent: Click to Email
We are developing a large-area display and a wearable health checker by weaving fibers with an electrical circuit on their surface. In this technique, a guide structure that determines the position to fix fibers was processed on the fiber by a thermal nanoimprint technology. We used two kinds of molds with guide structures with different cross-sectional shapes (rectangle and arc). Micropoles to connect the fiber were arranged in the bottom side of the guide structures. In the case of guide structure with a rectangular pattern, the multilayer structure was formed on a Si substrate using MEMS technology; and Ni mold was made by electroforming. Fifteen convex rectangles with their length, width, and height as 14.4 mm, 100 μm and 50 μm were arranged in a 1-mm pitch formation. And, 10-μm deep column holes with the diameters of 5, 10, and 20 μm, were fabricated on the upper side of the guide structure. The other kind of guide structure with an arc pattern was processed by precision machining. A 150-μm-thick Ni-P layer was electroless-plated on an Inconel-600 alloy substrate and the layer was then coarse-processed by dicing. The finish processing employed a 20-μm-diameter diamond endmill and a Robonano α-0iB (FANUC Ltd.). Thirteen arc guide structures with 20-μm-diameter holes were processed for 4 hrs. The length, bottom-width, and height of the individual guide structure were 15 mm, 160 μm, and 100 μm. Hemispherical holes with 20 μm diameter and a maximum depth of 10 μm were processed on the upper side of the guide structure. The size of each type of mold was the same 20 mm square. The guide structures from the two kinds of molds were imprinted on a 90-μm-diameter nylon fiber (Amilan, Toray Industries, Inc). In the imprinting experiments, a desktop thermal nanoimprint system NI-273 (Nano Craft Technologies Co.) was used. Molding conditions were: heating temperatures = 100 °C, cooling temperature = 70 °C, loading force = 100 N, and holding time = 1 s. The guide structure and micropoles were successfully transcribed from the mold onto the nylon fiber. The side-view of the guide structure was examined with an optical microscope and the pressed depth was measured as 21 μm, regardless of the kind of mold used. After the imprinting, the weaving of the fiber was carried out with tweezers under an optical microscope. Each guide was confirmed to be connected to each fiber. It was easy to weave the arc guide structure processed with machining because the guide sidewall was curved. In future, weaving of fiber with variety of electric circuit patterns will be presented.