3차원 플리츠 직물 구조물의 슬라이딩 거동에 따른 마찰전기 특성 분석

Abstract

With the growing demand for self-powered wearables, lot of interest in energy generating devices that can continuously power wearable devices, and studies on triboelectric generator devices are continuously increasing. Triboelectricity refers to an electrical signal generated by the physical contact of different materials. The efficiency of triboelectricity is influenced by various factors, including material selection, structural design, and notably, the specific surface area. There is a limit to increasing output performance by using materials, so studies are being conducted to analyze electrical signals by expanding the contact specific surface area through surface area shape and structural design. Increasing the contact area is the simplest way to improve the total number of charges generated, and more output performance can be achieved by applying roughness due to microstructures to the contact surface (Kim et al, 2020). As a related study, studies were conducted to manufacture triboelectric generating devices based on three-dimensional structural forms producing by knit(Niu et al, 2022) and fabric(Choi et al, 2017), and the electrical properties according to sliding, rubbing, stretching, and pressing were analyzed. Unlike two-dimensional structures, these three-dimensional structures play a key role in increasing output detection sensitivity even in environments with low external shocks(Lin et al, 2018). In this way, research on triboelectricity by textiles is conducted, but various structural designs of fabrics studies is insufficient. In this study a three-dimensional geometric pleats structure was produced by fabrics, and expected to increase the ability to generate energy by expanding the surface area through fabrics with specific microstructures. The impact of sliding behavior on electrical signals was analyzed using a three-dimensional pleats structure, and this sliding mode was conducted to view the contact area of the three-dimensional structure macroscopically. Nylon fabric was used as a positive charge, and Polytetrafluoroethylene (PTFE) fabric was used as a negative charge, and the pleated structure was manufactured by folding and then the shape was fixed through a sewing process. To analyze the characteristics of the triboelectricity of three-dimensional structure, a pleat structure was manufactured with different height and number. A conductive fabric was attached to the bottom of the structures to be used as an electrode, and triboelectric generator consisted of an upper structure with a Nylon pleats and a lower structure with an PTFE pleats. The upper and lower structures were fixed to the linear motor, and then the lower substrate was subjected to sliding motion. The contact, sliding, and separation behaviors were demonstrated in sequence and generated electric signals of each behaviors were analyzed the characteristics of electrical signals. The characteristics of electrical signals were analyzed through the height and number of pleats, which are structural shape characteristics. In addition the characteristics of the electrical signal were analyzed by controlling the driving of moving distance, speed and distance between the upper and lower parts of the glissando behavior. The results of the experiment are as follows. First, as the height and number of pleats increase, contact surface area between the upper and lower structures increased, so electrical properties has been also increase. Second, the range of sliding mode distance increases, this increases contact area by dynamic drive so the intensity and width of the electrical signal increased. Third, if sliding speed increased, by friction the electrical signal also increase, while the width of the electrical signal gradually narrowed, which was caused by a relatively short contact/sliding/separation behavior time as the speed increased. Fourth, it was confirmed that the electrical characteristics were improved by increasing the contact area by gradually narrowing the upper and lower intervals in the glissando behavior which refers to the structure, rub the pleats against each other. In summary, triboelectric generator of a three-dimensional pleats fabric structure was manufactured, and confirmed that if the shapes of the structure were deformed, it affects electrical characteristic. And the sliding mode behavior of the triboelectric generator itself affects electrical characteristics. This study is valid in analyzing electrical signals on a macroscopic scale through the design of a fabric based on three-dimensional pleats structure. And demonstrated results will pave the way of understanding how to optimize the electrical signal of the three-dimensional fabric-based structure triboelectric generator with respect to its structure.