• 한국정밀공학회지
• /
• 제26권9호
• /
• pp.143-147
• /
• 2009

Inkjet printing makes use of ink droplets to form required patterns on a substrate. In order for the inkjet technology to produce reliable patterning tools, the jetting performance needs be controlled precisely. For controlling ink jetting performance, input waveform should be properly designed. In the past, the research was focused on designing dwell time of the input waveform for controlling jetting speed. However, the jetting performance is also closely related to rising and falling time. In this study, the effect of the rising and falling time on droplet speed will be investigated by measuring the droplet speed. In this study, the power OP amp (PA98A) was used in order to drive piezo inkjet head by amplifying the waveform generated from arbitrary function generator. The experimental results show that change of rising and falling time in the waveform not only affect the droplet speed but also optimal dwell time.

• 한국결정성장학회지
• /
• 제29권6호
• /
• pp.352-358
• /
• 2019

최근 인쇄용지는 단순히 정보 전달의 기능을 넘어서 미적, 예술적 가치가 부가면서 고품질의 인쇄가 가능한 도공지(coated paper)에 대한 시장의 수요가 증가하고 있다. 특히 실사급 고품질의 인쇄가 가능한 잉크젯 프린팅의 도공지는 잉크의 인쇄적성을 향상시키기 위하여 표면에 젖음성(wettability)과 다공성 구조(porous structure)를 갖는 도공층의 역할이 매우 중요하다. 본 연구에서는 나노 실리카 졸 입자에 실란 커플링제로 표면처리하고 수용성 결합제인 폴리비닐알콜(PVA)와 혼합하여 도공액(coating color)를 제조하고 원지(base paper)에 코팅하여 도공층을 제조하였다. 실란 커플링제로 표면처리한 나노 실리카 도공층은 표면처리하지 않은 도공층과 비교하여 균일한 기공 분포 및 평탄한 표면 거칠기를 가지며, 판매용 고급 인화지와 유사한 광택도를 갖는 것을 확인하였다. 특히 잉크의 망점(dot)에 대한 진원도로 평가하는 인쇄적성 평가 결과 실란 커플링제로 표면처리한 도공지는 다층 구조의 도공층을 갖는 판매용 고급 인화지보다 더 우수한 결과를 얻을 수 있었다. 이러한 결과는 실란 커플링제 표면처리를 통하여 나노 실리카 입자의 분산성이 향상되어 우수한 젖음성과 균일한 기공 분포를 갖는 도공층 형성이 가능하였기 때문으로 확인되었다.

• 대한의용생체공학회:의공학회지
• /
• 제39권5호
• /
• pp.188-207
• /
• 2018

Recently, three-dimensional (3D) printing of biological tissues and organ has become an attractive interdisciplinary research topic that combines a broad range of fields including engineering, biomaterials science, cell biology, physics, and medicine. The 3D bioprinting can be used to produce complex tissue engineering scaffolds based on computer designs obtained from patient-specific anatomical data. It is a powerful tool for building structures by printing cells together with matrix materials and biochemical factors in spatially predefined positions within confined 3D structures. In the field of the 3D bioprinting, three major categories of the 3D bioprinting include the stereolithography-based, inkjet-based, and dispensing-based bioprinting. Some of them have made significant process. Each technique has its own advantages and limitations. Compared with non-biological printing, the 3D bioprinting should consider additional complexities: biocompatibility, degradability of printing materials, cell types, cell growth, cell viability, and cell proliferation factors. Numerous 3D bioprinting technologies have been proposed, and some of them have been making great progress in printing several tissues including multilayered skin, cartilaginous structures, bone, vasculature even heart and liver. This review summarizes basic principles and key aspects of some frequently utilized printing technologies, and introduces current challenges, and prospects in the 3D bioprinting.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1523_1524
• /
• 2009

Inkjet technology has various merits as a direct patterning process in plenty of industrial applications, but critical issue such as coffee ring effect should be overcome for the application to an industrial manufacturing process. In this paper, we introduced the morphological analysis of inkjet printed pattrerns on the characristics of inks and substrates. In case of Triethlene Glycol Monoethly Ether based ink, the coffee ring effect was observed. However, an ethanol based ink showed the round shaped morphology under the same printing conditions and surface conditions. An ink consisted of the solvent with high boiling point results in coffee ring effect. This experimental results showed that the morphological change of the printed droplet is caused by the main solvent of ink, rather than the metal content, viscosity and surface tension.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1497-1500
• /
• 2006

Inkjet printing technology can reduce the LCD color filter manufacturing cost more than 50 %. Uniform color filter patterning can be achieved only with proper ink and barrier materials. We developed new ink and black matrix materials for inkjet color filter. The ink materials have low volatility while they have very high solid content. The black matrix materials have very precisely controlled surface energy so that the inks can fill the pixels evenly and completely. We controlled the ink drop volume and ink material to minimize the thickness difference between the black matrix and the color pixel. Micron-order jetting position accuracy was achieved. We successfully printed 14.1" color filters using our ink and black matrix materials.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
• /
• pp.922-925
• /
• 2005

Inkjet printing technology is a highly proprietary process. We have evaluated the possibility of using inkjet technique to prepare color filters. Product specification for TV application was used as a template to examine process capability. Technical aspects of ink composition, jetting ability, and surface interaction were discussed.

• Journal of Information Display
• /
• 제12권4호
• /
• pp.199-203
• /
• 2011

Reported herein is the film morphology control of inkjet-printed 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) organic thin-film transistors for the improvement of their performance and of the device-to-device uniformity. The morphology of the inkjetted TIPS-pentacene films was significantly influenced by the bank geometry such as the bank shapes and confinement area for the channel region. A specific confinement size led to the formation of uniform TIPS-pentacene channel layers and better electrical properties, which suggests that the ink volume and the solid concentration of the organic-semiconductor solutions should be considered in designing the bank geometry.

• 한국정보통신학회논문지
• /
• 제17권2호
• /
• pp.263-272
• /
• 2013

인쇄전자는 다양한 기판에 기능적 소자를 프린팅한다. 인쇄방법은 스크린 인쇄, 플렉소그라피, 오프셋 리소그라피와 잉크젯 방식을 통해 적정한 패턴을 만든다. 인쇄기법을 응용하여 활용하기 때문에 전통적인 극소전자공학에 비하여 생산과정이 간단하고 비용 또한 저렴하다. 잉크젯 및 R2R(Roll to Roll)기술이 발전을 거듭해 왔기 때문에 디스플레이에서 태양전지의 제조까지 그 기술이 활용된다. IDTech(2010)에 의하면, 전자인쇄시장은 2010년에 10.99(억달러)에서 2020년 55.10(억달러)로 커질 것이며, 2030년에는 반도체산업의 규모보다 큰 3,000억 달러가 될 것으로 전망하고 있다. 센서, 배터리, 광전지, 메모리, 스마트카드 시장이 확대되는 등 조명에서 디스플레이까지 인쇄전자산업시장은 성장할 것이다.

• 센서학회지
• /
• 제24권2호
• /
• pp.119-123
• /
• 2015

This paper presents the inkjet-printed flexible temperature and humidity sensor(F-TH sensor) using PEDOT:PSS. The series, mesh and parallel type sensing element using PEDOT:PSS ink was printed on the overhead projector(OHP) film. The fabricated sensor of each structure has the temperature sensitivity of $140{\Omega}/^{\circ}C$, $29{\Omega}/^{\circ}C$ and $1.4{\Omega}/^{\circ}C$ with linearity, respectively. Also the fabricated sensor was not only possible to measure a temperature, but also to detect humidity. The humidity sensitivity of $400{\Omega}/%RH$, $3.4{\Omega}/%RH$ and $3{\Omega}/%RH$ with linearity, respectively. The fabricated F-TH sensor is expected for the various applications such as electronic devices, bio-healthcare, industrial field.

• 한국전기전자재료학회논문지
• /
• 제35권6호
• /
• pp.547-555
• /
• 2022

Color conversion layer refers to a layer that converts the blue light emitted from the backlight into the red and green light. Heavy metal-free quantum dots and perovskite nanocrystals have attracted great attention as base materials for color conversion layers due to their outstanding optical characteristics. Here, we review recent advances in the development of color conversion layers based on quantum dots. First, we overview the representative optical characteristics of quantum dots and perovskite nanocrystals, and then introduce printing techniques for color converting layers including photolithography, inkjet printing, and nanoimprinting. Finally, we conclude this review with a brief perspective.