Continuous Fabrication of Wide-Tip Microstructures for Bio-Inspired Dry Adhesives via Tip Inking Process

Abstract

In this paper, we report a new method for continuous fabrication of dry adhesives composed of microstructures with mushroom-shaped ends. Conventional mushroom microstructure fabrication is performed with a simple molding technique using a reversed phase master. In a typical fabrication process, thin- and wide-tip portions may be ripped during demolding, making it difficult to use in a continuous process. It is also difficult to apply the mushroom structure master to a continuous process system in roll form. Here, a continuous fabrication process was developed by applying the method of fabricating a wide tip using a tip inking method after forming a micropillar. Through the continuous process, the dry adhesive was successfully fabricated and the durability was measured with a reasonable pull-off strength (13 N/cm2). In addition to the reasonable adhesion, high durability is guaranteed, and fabricated dry adhesives are expected to be used in various fields.

Facile fabrication of high-density mushroom-shaped microstructures using the photo-lithographic technique

“…DRIES enables controllable and high-resolution fabrication of mushroomshaped microstructures, however, the high cost and limited area of the semiconductor process were issues with regard to the commercialization of mushroom-shaped microstructures as dry adhesives and hydrophobic surfaces. A cap inking method was developed to enable continuous and cost-effective fabrication of mushroom-shaped microstructures, where the straight micropillar caps were first inked with curable resin and then pressed against a low surface energy plane for subsequent curing [18][19][20]. This approach is relatively simple but has difficulty in obtaining uniform and dense mushroom-shaped microstructues because of the fluidic nature of uncured prepolymer and the mechanical accuracy of coating and pressing.…”