• 한국표면공학회지
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• 제54권6호
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• pp.324-330
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• 2021

As energy harvesting technology becomes important in relation to environmental issues, piezoelectric materials that convert mechanical energy into electrical energy are attracting attention. However, PZT, a representative material for piezoelectricity, is becoming difficult to use due to the problem that its components can cause environmental pollution. For this reason, recent research suggests a triboelectric nanogenerator (TENG) that generates energy through the combined effect of triboelectricity and electric induction for alternative piezoelectric devices. In TENG, electrical power is determined by the dielectric constant, thickness, and grain generation of the charged material. Therefore, in this study, a Rutile phase TiO₂ thin film with high dielectric constant was formed using the spin-coating process and the effect of annealing was investigated. For electrical analysis, a TENG device was fabricated using PTFE as a material with an opposite charge, and electrical output according to film thickness and grain formation was comparatively analyzed.

• 한국응용과학기술학회지
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• 제40권4호
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• pp.913-923
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• 2023

본 연구에서는 공기중에서도 안정적이며 상대적으로 전기음성도가 큰 테플론계열의 고분자와 그래핀플라워를 이용하여 마찰전기 나노발전기를 제작하였다. 상기 복합고분자는 회전도포방법을 이용하여 나노발전기의 전기적 음성층의 제작에 이용되었다. 전기적 양성층을 위하여 졸-겔 방법을 이용하여 산화아연막을 제작하였다. 제작된 마찰전기 나노발전기는 약 44 ㎼의 최대전력을 생산하였다. 결론적으로, 마찰전기 나노발전기의 모든 활성층은 회전도포방법을 이용하였으므로 대면적으로 확장가능하다.

• Tribology and Lubricants
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• 제40권4호
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• pp.118-132
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• 2024

The triboelectric nanogenerator (TENG) has emerged as a groundbreaking technology for harvesting clean and sustainable energy cost effectively. For reliable TENG design, minimizing wear damage at the friction layers is crucial. This review provides a comprehensive overview of tribometer-integrated TENG testing configurations used in the simultaneous investigation of both tribological and electrical performance. It considers configurations such as plate-on-plate, ball-on-disc, and ball-on-flat tribometers designed for linear reciprocating or rotating sliding friction tests. These tribometers are either specifically designed or adapted for TENG testing. Triboelectric material holders facilitate friction tests by establishing electrical connections from the triboelectric materials or electrodes, thereby enabling accurate measurement of electrical signals. Electrometers and oscilloscopes record electrical outputs such as short-circuit current and open-circuit voltage. This integration enables the simultaneous measurement of both friction and electrical outputs, providing a thorough understanding of TENG performance. The review also summarizes how factors such as normal force, sliding frequency, and rotating speed affect friction coefficients and TENG performance. It also examines the relationship between the coefficient of friction and tribocharges under various loads and frequencies. The review emphasizes the importance of these testing configurations for evaluating both friction and electrical performance, which are crucial for optimizing TENG efficiency. Finally, the review explores future prospects for developing innovative tribometer designs suited for both tribology and TENG testing.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.631-631
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• 2013

Battery has major drawbacks including its size and life expectancy, and environmental problem. As an alternative, energy harvesting is emerging as a potential solution to replace battery along with more energy-efficient IT devices. The idea of harnessing energy from our living environment is sustainable, semi-permanent, and eco-friendly. Also, unlike battery, energy harvester does not require much space to store energy. Therefore, energy harvesting can provide a better source of power for small, portable, and wireless devices. Among various ways of harvesting energy from our surroundings, triboelectricity is chosen due to its potential to be miniaturized, and efficient. Triboelectric effect occurs as two different materials with different polarity of charge separation come into contact through friction, and then become separated so that electric potential difference is achieved. In this research, such characteristic of triboelectricity is used as a way to convert ambient mechanical energy into electric energy.Series of recent researches have shown promising results that the triboelectric energy harvester can be simple and cost effective. However, sufficient electricity level required to operate mobile devices has not yet been achieved.In this research, our group focuses on the design and optimization of triboelectric energy harvesting device to enhance its output. By using maskless lithography to pattern Kapton film and silicon substrate, which is used as a mold for PDMS thin layer, and sputtering metal electrodes on each side, we fabricate and demonstrate different designs of triboelectric energy harvester that utilizes the contact electrification between a polymer thin film and a metal thin foil. In order to achieve optimized result, the output voltage and current are measured under diverse conditions, which include different surface structure and pattern, material, and the gap between layers.

• 한국응용과학기술학회지
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• 제40권1호
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• pp.179-187
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• 2023

바이오물질을 포함하는 나노발전기는 무공해 에너지원이며 생분해성 전자폐기물이라는 점에서 친환경적인 전자소자이다. 특히 바이오 물질이 바이오폐기물로부터 추출될 수 있다면 바이오폐기물의 양도 줄어들 것이다. 본 연구에서는 포유동물의 피부에 존재하는 동물성 콜라겐을 이용하여 마찰전기 나노발전기를 제작하였고 그 특성평가를 진행하였다. 마찰전기 나노발전기의 전기적 양극층은 회전 도포방법을 이용하여 콜라겐 막을 형성하여 구성하였으며, 주사전자현미경으로 막이 다공성임을 확인하였다. 제작한 마찰전기 나노발전기는 주기적인 기계적 운동에 의해 3 Hz에서 7 V부터 5 Hz에서 15 V의 개방전압과 5 Hz에서 3.8 ㎂의 단락전류를 보였다. 결론적으로, 콜라겐 함유 마찰전기 나노발전기는 센서와 같은 저전력 구동 장치의 전원이 될 수 있으며 전자 폐기물 감소에도 유용할 것으로 기대된다.

• Composites Research
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• 제36권3호
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• pp.224-229
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• 2023

최근 각종 전자기기의 소형화와 웨어러블 디바이스의 수요가 증가함에 따라 IT 기기들의 나노화가 진행되는 추세이며, 이에 따른 배터리의 크기 및 용량 등의 한계를 극복하기 위하여 에너지 하베스팅 기술인 마찰 대전에 대한 연구가 많은 관심을 받고 있다. 불소계 코팅을 진행한 양극산화 알루미늄은 대전 서열에서 음극 성향이 높은 대전층과 대전된 전하가 전극으로 손실없이 전달되도록 도와주는 절연층 그리고 전극을 모두 포함하고 있는 구조로서 마찰 대전 나노발전기의 적용에 있어 많은 연구가 진행되어 왔다. 본 연구에서는 마찰대전 나노발전기 적용에 유리한 양극산화 알루미늄을 활용하여 마찰대전 나노발전기에 영향을 미치는 표면 형상 및 절연층의 두께를 조절하여 발전량과의 상관관계에 대하여 분석하였다. 이러한 분석을 통하여 추후 마찰대전 나노발전기 제작에 있어 면적 대비 발전량을 증가시킬 수 있는 방향을 제시할 수 있었다.

• 세라미스트
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• 제22권2호
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• pp.110-121
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• 2019

Triboelectric nanogenerators and piezoelectric nanogenerators are a spotlighted energy harvesting method that converts the wasted mechanical energy from the environment into usable electrical energy. In the case of triboelectric nanogenerators, researches have been mainly focused on high permittivity and flexible polymer materials, and in the case of piezoelectric nanogenerators, researches have been focused on ceramic materials exhibiting high polarization characteristics. Recently, many researches have been conducted to improve durability and power in various environments by using composite materials which have flexible properties of polymer, high permittivity, thermal resistance and high polarization properties of ceramics. This article reviews the energy harvesting studies reported about composites materials using ceramics and polymers.

• 한국분말재료학회지
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• 제30권6호
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• pp.528-535
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• 2023

Since their initial development in 2012, triboelectric nanogenerators (TENGs) have gained popularity worldwide as a desired option for harnessing energy. The urgent demand for TENGs is attributed to their novel structural design, low cost, and use of large-scale materials. The output performance of a TENG depends on the surface charge density of the friction layers. Several recycled and biowaste materials have been explored as friction layers to enhance the output performance of TENGs. Natural and oceanic biomaterials have also been investigated as alternatives for improving the performance of TENG devices. Moreover, structural innovations have been made in TENGs to develop highly efficient devices. This review summarizes the recent developments in recycling and biowaste materials for TENG devices. The potential of natural and oceanic biowaste materials is also discussed. Finally, future outlooks for the structural developments in TENG devices are presented.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.415.2-415.2
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• 2016

Triboelectric nanogenerator (TENG) is one of ways to convert mechanical energy sound, waves, wind, vibrations, and human motions to available electrical energy. The principal mechanism to generate electrical energy is based on contact electrification on material surface and electrostatic induction between electrodes. The performance of TENG are dependent on amount of the input mechanical energy and characteristics of triboelectric materials. Furthermore, the whole TENG system including mechanical structure and electrical system can effect on output performance of TENG. In this work, we investigated the effect of gear train on output performance and power conversion efficiency (PCE) of TENG under a given input energy. We applied the gear train on mechanical structure to improve the contact rate. We measured the output energy under a constant input energy by controlling the size of the working gear. We prepared gears with gear ratios (rin/rw) of 1, 1.7, and 5. Under the constant input energy, the voltage and current from our gear-based TENG system were enhanced up to the maximum of 3.6 times and 4.4 times, respectively. Also, the PCE was increased up to 7 times at input frequency of 1.5 Hz. In order to understand the effect of kinematic design on TENG system, we performed a capacitor experiment with rectification circuit that provide DC voltage and current. Under the input frequency of 4.5 Hz, we obtained a 3 times enhanced rectifying voltage at a gear ratio of 5. The measured capacitor voltage was enhanced up to about 8 fold in using our TENG system. It is attributed that our gear-based TENG system could improve simultaneously the magnitude as well as the generation time of output power, finally enhancing output energy. Therefore, our gear-based TENG system provided an effective way to enhance the PCE of TENGs operating at a given input energy.

• Composites Research
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• 제32권6호
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• pp.307-313
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• 2019

Triboelectric nanogenerators (TENGs)는 정전기 기반의 마찰 전기 발전기로써 간단한 구조로 저비용, 대면적으로 손쉽게 활용할 수 있는 기술이다. 본 연구에선 생활 용품을 활용하여 화학적 결합 및 SEM image로써 분석을 하고 C-C/C-H/C-O/C=O bonding에 따라 bonding 조성비에 따라 C-C bonding의 비율이 클수록 음전하, C-H bonding 비율이 클수록 양전하 대전체가 되는 것을 확인하였다. 그러한 특성을 가지고 최적 생활용품을 활용하여 정전 출력 실험을 했을 때 최대 210 V, 14.6 ㎂, 9.83 mW의 출력을 얻었다. 최종적으로, 랩과 마그네틱 노트를 이용해 97개의 Light Emitting Diodes (LEDs)를 점등할 수 있었다.