• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.233-235
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• 2019

에너지 하베스팅은 주변의 에너지를 수확하여 활용하는 기술로 이에 관련한 연구가 여러 분야에서 활발히 진행되고 있다. 마찰전기 나노발전기는 물리적인 움직임이나 마찰을 통해 발생되는 정전기를 이용하여 센서나 웨어러블 디바이스에 활용하는 에너지 하베스팅 기술 중 하나이다. 마찰전기 나노발전기는 ${\mu}W$(마이크로와트) 단위의 미소 전력을 생산함에도 불구하고, 다른 에너지 하베스팅 발전기들과 비교하여 큰 임피던스를 가지고 있어서 전력을 전달하기에 어려움이 있다. 또한 마찰전기 나노 발전기의 출력 전력은 Spike성 Pulse Train의 형태여서 다이오드 정류기가 필요하기 때문에, 정류기의 입력 임피던스와 마찰전기 나노 발전기의 출력 임피던스에 대한 분석을 이용한 임피던스 매칭 설계가 필요하다. 본 연구에서는 다이오드 정류기의 임피던스 모델을 유도하여 마찰전기 나노 발전기의 내부 임피던스와의 매칭을 통해 최대 전력을 전달하는 커패시터와 출력 부하 설계를 목표로 한다. 유도한 임피던스 모델에 대하여 실제 전력 실험을 통해 모델의 유효성과 정확성을 검증하고자 한다.

• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.913-923
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• 2023

In this study, a triboelectric nanogenerator was fabricated using the composite of teflon-based polymer and graphene flower, which are stable in air and have relatively high electronegativity. The composite was used to fabricate an electronegative layer of a nanogenerator using a spin-coating method. For the electropositive layer, a zinc oxide film was prepared using a sol-gel method. The fabricated triboelectric nanogenerator produced a maximum power of about 44 ㎼. In conclusion, since all the active layers of the triboelectric nanogenerator was made by the solution process, it is scalable to a large area.

• Journal of the Korean Applied Science and Technology
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• v.40 no.1
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• pp.179-187
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• 2023

Nanogenerators containing biomaterials are eco-friendly electronic devices in terms of being a non-polluting energy source and biodegradable electronic waste. In particular, the amount of waste will be also reduced if the biomaterial can be extracted from biowaste. In this study, a triboelectric nanogenerator was fabricated using animal collagen present in the skin of a mammal and its characteristion was proformed. The electro-anodic layer of the triboelectric nanogenerator was constructed by forming a collagen film using the spin coating method, and it was confirmed that the film was porous from scanning electron microscopy. The fabricated triboelectric nanogenerator exhibited an open-circuit voltage from 7 V at 3 Hz to 15 V at 5 Hz due to periodic mechanical movement, and a short-circuit current of 3.8 uA at 5 Hz. In conclusion, collagen-containing triboelectric nanogenerators can be power source for low-power operating devices such as sensors and are also expected to be useful for reducing electronic waste.

• Composites Research
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• v.36 no.3
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• pp.224-229
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• 2023

Due to the increasing demand for wearable devices and miniaturization of various electronic devices, the trend of nanofabrication in IT devices is underway. In order to overcome the limitations of battery size and capacity, there has been a lot of research interest in energy harvesting technology, also known as triboelectric nanogenerator. AAO(Anodic Aluminum oxide) coated with fluoride is a structure that includes an anode layer with high properties in the triboelectric series, an dielectric layer that helps transfer the triboelectrically generated charges to the electrode without loss, and the electrode. For these reasons, AAO has been a lot of research on its application to frictional energy harvesting nanogenerators. In this work, we analyzed the correlation of AAO between the surface morphology and thickness of the insulating layer by utilizing aluminum oxide, which is advantageous for the application of triboelectric nanogenerators, and adjusting the thickness of the insulating layer.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.65.2-65.2
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• 2013

발광다이오드, 태양전지, 광센서, 바이오센서, 나노발전기 등을 포함한 여러 종류의 광전자 소자들의 성능을 향상시키기 위한 새로운 기술적 시도들이 제안되어 왔다. 반도체기반 나노구조는 넓은 표면적과 독특한 특성을 가지고 다양한 기능성의 부여가 용이하며, 주로 나노패턴형성 및 식각에 의한 top-down 방법과 성장/합성에 의한 bottom-up 방법들에 의해 제작되어 왔다. 최근, 단순성, 저비용 공정을 바탕으로 소자 표면상에 나노구조를 형성하여 성능을 개선하기 위한 연구가 활발히 이루어지고 있다. 또한 다층박막을 통한 무반사 코팅을 대체할 수 있는 moth-eye 효과를 이용한 생체모방형 서브파장 무반사 나노구조에 대한 관심이 증가하고 있다. 본 발표에서는 실리콘, 화합물, 산화물을 포함한 반도체 나노구조들의 설계 및 제작을 통해 구조적, 광학적 특성을 측정, 분석하고 이들의 다양한 광전자소자 응용에 대한 연구결과를 발표하고자 한다.

• Composites Research
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• v.35 no.6
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• pp.371-377
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• 2022

Triboelectric nanogenerator (TENG) devices have generated a lot of interest in recent decades. TENG technology, which is one of the technologies for harvesting mechanical energy among the energy wasted in the environment, is obtained by the dual effect of electrostatic induction and triboelectric charging. Recently, a multilayer thin film stacking method (or layer-by-layer (LbL) self-assembly technique) is being considered as a method to improve the performance of TENG and apply it to new fields. This LbL assembly technology can not only improve the performance of TENG and successfully overcome the thickness problem in applications, but also present an inexpensive, environmentally friendly process and be used for large-scale and mass production. In this review, recent studies in the accomplishment of LbL-based materials for TENG devices are reviewed, and the potential for energy harvesting devices reviewed so far is checked. The advantages of the TENG device fabricated by applying the LbL technology are discussed, and finally, the direction and perspective of this fabrication technology for the implementation of various ultra-thin TENGs are briefly presented.

• Tribology and Lubricants
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• v.37 no.4
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• pp.125-128
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• 2021

A means of enhancing the performance of triboelectric nanogenerators (TENGs) is increasing the differences in work functions between contacting materials. Hexagonal boron nitride (h-BN) exhibits excellent mechanical properties and high chemical stability as well as a high work function. As a result, engineers in the field of energy harvesting have envisioned using h-BN in the electrification layer in TENGs. For the industrial application of h-BN in TENGs, large-scale production is necessary, and h-BN is generally exfoliated and dispersed in various solvents. In this study, we evaluate the performance of a TENG with h-BN nanoflakes in the polyimide (PI) layer. To synthesize a PI composite containing h-BN nanoflakes, h-BN powders are exfoliated and dispersed in poly(amic acid) (PAA), which is the precursor of PI. Then, h-BN dispersion is spin-coated onto the PI film and cured for 2 h under 300℃. This composite material can then be used for the electrification layer in TENGs. Below the electrification layer, an aluminum foil is placed and used as an electrode. When the contact and separation processes with polyethylene terephthalate are repeated, the fabricated TENG shows a maximum power density of 190.8 W/m². This study shows that h-BN is a promising material for enhancing the performance of the electrification layer in TENGs.

• Vacuum Magazine
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• v.3 no.2
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• pp.17-20
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• 2016

Piezoelectric nanogenerators are energy harvesting device to convert a mechanical energy into an electric energy using nanostructured piezoelectric materials. This review summarizes works to date on piezoelectric nanogenerators, starting with a basic theory of piezoelectricity and working mechanism, and moving through the reports of numerous nanogenerators using nanorod arrays, flexible substrates and alternative materials. A sufficient power generated from nanogenerators suggests feasible applications for either power supplies or strain sensors of highly integratedl nano devices. Further development of nanogenerators holds promise for the development of self-powered implantable and wearable electronics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.213-214
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• 2007

에폭시/마이카는 높은 절연성과 강도, 열 안정성 등으로 인하여 고전압 회전기 고정자 권선의 절연재료로 사용되고 있다. 그러나 최근 청단기기의 등장과 냉난방 부하의 증가로 첨두 부하가 크게 증가하여 발전기 부하변동과 자동 정지횟수가 빈번해지고 있다. 이에 따라 기존에 사용되고 있는 절연재료를 획기적으로 발전시킨 새로운 소재의 개발이 필요하게 되었다. 최근 나노기술은 이러한 기술적 한계를 극복할 수 있는 좋은 대안으로 떠오르고 있다. 그리고 나노 크기의 층상화합물은 기존의 재료에 비해 월등한 전기적, 기계적, 열적 특성을 지닌 것으로 알려져 있다. 본 논문에서는 에폭시 기지에 층상 마이카와 점토를 혼합한 나노복합재료를 제조하여 주파수별, 온도별 유전특성을 살펴보았다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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• pp.9-15
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• 2022

Discarded bio-wastes, such as seeds and rinds, cause environmental problems. Multiple studies have recycled bio-wastes as eco-friendly energy sources to solve these problems. This study uses bio-waste to fabricate a mandarin peel powder based triboelectric nanogenerator (MPP-TENG). The MPP-TENG is based on the contact separation mode. It generates an open-circuit voltage and short-circuit current of 156V and 2µA, respectively. In addition, MPP-TENG shows stable operation over continuous 3000s without any deviation in output. Also, the device exhibits maximum power density of 5.3㎼/cm² when connected to a resistance of 100MΩ. In an energy storage capacity test for 1000s, the MPP-TENG stores an energy of 171.6µJ in a 4.7µF capacitor. The MPP-TENG can power 9 blue LEDs and 54 green lettering LEDs. These results confirm that the MPP-TENG can provide a new avenue for eco-friendly energy harvesting device fabrication.