• 전자통신동향분석
• /
• 제36권3호
• /
• pp.65-75
• /
• 2021

In the era of the 4th industrial revolution, interest in flexible devices is increasing for information and communication technology electronic products. This is a hot technology field in which competition is intensifying to preoccupy the global market for flexible electronic devices because of the many advantages of ultra-lightweight, flexibility, design diversity, high applicability, and low cost. Some flexible electronic products have been commercialized in Korea, but they are still inadequate in terms of price versus performance, so technology development is required continuously. Particularly, the development of flexible electronic materials is emerging as a key factor for flexible electronic device applications. In this study, we will look into the flexible electronic material technology and industry trends following the trend of flexible technology changes in the display, secondary battery, and solar cell, which has emerged as national core industry and has secured global competitiveness. In addition, I want to introduce the Flexible Electronic Material Center, which was established to foster the flexible electronic material industry.

• 한국기계가공학회지
• /
• 제19권1호
• /
• pp.63-71
• /
• 2020

Recently, to improve convenience, flexible electronics are quickly being developed for a number of application areas. Flexible electronic devices comprise characters such as being bendable, stretchable, foldable, and wearable. Effectively manufacturing flexible electronic devices requires high efficiency, low costs, and simple processes for manufacturing technology. Through this study, we enabled the rapid production of multifunctional flexible bending sensors using a simple, low-cost Fused Deposition Modeling (FDM) 3D printer. Furthermore, we demonstrated the possibility of the rapid production of a range of functional flexible bending sensors using a simple, low-cost FDM 3D printer. Accurate and reproducible functional materials made by FDM 3D printers are an effective tool for the fabrication of flexible sensor electronic devices. The 3D-printed flexible bending sensor consisted of polyurethane and a conductive filament. Two patterns of electrodes (straight and Hilbert curve) for the 3D printing flexible sensor were fabricated and analyzed for the characteristics of bending displacement. The experimental results showed that the straight curve electrode sensor sensing ability was superior to the Hilbert curve electrode sensor, and the electrical conductivity of the Hilbert curve electrode sensor is better than the straight curve electrode sensor. The results of this study will be very useful for the fabrication of various 3D-printed flexible sensor devices with multiple degrees of freedom that are not limited by size and shape.

• 한국전기전자재료학회논문지
• /
• 제37권3호
• /
• pp.241-252
• /
• 2024

With the recent development of emerging technologies, information acquisition and delivery between users has been actively conducted, and inorganic thin film transfer technology that effectively transfers various materials and devices is being studied to develop flexible electronic devices accordingly. This is aimed at innovative structural changes and functional improvement of electronic devices in the era of the Internet of Things (IoT). In particular, advanced technologies such as microLEDs are used to realize high-resolution flexible displays, and the possibility of heterogeneous integrated technologies can be presented by precisely transferring materials to substrates through various transfer process. This paper introduced physical, chemical, and self-assembly transfer methods based on inorganic thin film materials to implement heterogeneous integrated flexible semiconductor systems and introduces the results of application studies of semiconductor devices obtained through different transfer technologies. These studies are expected to bring about innovative changes in the field of smart devices, medical technology, and user interfaces in the future.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 하계학술대회 논문집
• /
• pp.218-221
• /
• 2002

We have successfully developed the high performance flexible thin film diode device for flexible plastic film LCD. For flexible LCD, TFD device must be normally operated under any deformation state. Two type devices, Ti/Ta$_2$O$\sub$5//Ta and Al/Ta$_2$O$\sub$5//Al were fabricated and the symmetry and reliability of those were estimated under various measurement conditions including severely bending states.

• 마이크로전자및패키징학회지
• /
• 제20권4호
• /
• pp.1-6
• /
• 2013

Recently, various types of flexible devices such as flexible displays, batteries, e-skins and solar cell panels have been reported. Most of the researches focus on the development of high performance flexible device. However, to realize these flexible devices, the long-term reliability should be guaranteed during the repeated deformations of flexible devices because the direct mechanical stress would be applied on the electronic devices unlike the rigid Si-based devices. Among various materials consisting electronics devices, metal electrode is one of the weakest parts against mechanical deformation because the mechanical and electrical properties of metal films degrade gradually due to fatigue damage during repeated deformations. This article reviews the researches of fatigue behavior of thin metal film, and introduces the methods to enhance the reliability of metal electrode for flexible device.

• 한국분말재료학회지
• /
• 제25권3호
• /
• pp.263-272
• /
• 2018

Recent developments in the field of energy harvesting technology that convert ambient energy resources into electricity enable the use of self-powered energy systems in wearable and portable electronic devices without the need for additional external power sources. In particular, piezoelectric-effect-based flexible energy harvesters have drawn much attention because they can guarantee power generation from ubiquitous mechanical and vibrational movements. In response to demand for sustainable, permanent, and remote use of real-life personal electronics, many research groups have investigated flexible piezoelectric energy harvesters (f-PEHs) that employ nanoscaled piezoelectric materials such as nanowires, nanoparticles, nanofibers, and nanotubes. In those attempts, they have proven the feasibility of energy harvesting from tiny periodic mechanical deformations and energy utilization of f-PEH in commercial electronic devices. This review paper provides a brief overview of f-PEH devices based on piezoelectric nanomaterials and summarizes the development history, output performance, and applications.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.211-214
• /
• 2009

In this paper we will outline the opportunities for flexible OLED devices, both for display and solid-state lighting applications. We will present our recent data, and discuss future challenges, for low power consumption phosphorescent OLED technology fabricated on flexible substrates to enable a new generation of energy efficient electronic devices.

• 마이크로전자및패키징학회지
• /
• 제20권2호
• /
• pp.1-9
• /
• 2013

Recently flexible electronic devices have attracted a great deal of attention because of new application possibilities including flexible display, flexible memory, flexible solar cell and flexible sensor. In particular, development of flexible memory is essential to complete the flexible integrated systems such as flexible smart phone and wearable computer. Research of flexible memory has primarily focused on organic-based materials. However, organic flexible memory has still several disadvantages, including lower electrical performance and long-term reliability. Therefore, emerging research in flexible electronics seeks to develop flexible and stretchable technologies that offer the high performance of conventional wafer-based devices as well as superior flexibility. Development of flexible memory with inorganic silicon materials is based on the design principle that any material, in sufficiently thin form, is flexible and bendable since the bending strain is directly proportional to thickness. This article reviews progress in recent technologies for flexible memory and flexible electronics with inorganic silicon materials, including transfer printing technology, wavy or serpentine interconnection structure for reducing strain, and wafer thinning technology.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.115-116
• /
• 2012

The demand for flexible electronic systems such as wearable computers, E-paper, and flexible displays has increased due to their advantages of excellent portability, conformal contact with curved surfaces, light weight, and human friendly interfaces over present rigid electronic systems. This seminar introduces three recent progresses that can extend the application of high performance flexible inorganic electronics. The first part of this seminar will introduce a RRAM with a one transistor-one memristor (1T-1M) arrays on flexible substrates. Flexible memory is an essential part of electronics for data processing, storage, and radio frequency (RF) communication and thus a key element to realize such flexible electronic systems. Although several emerging memory technologies, including resistive switching memory, have been proposed, the cell-to-cell interference issue has to be overcome for flexible and high performance nonvolatile memory applications. The cell-to-cell interference between neighbouring memory cells occurs due to leakage current paths through adjacent low resistance state cells and induces not only unnecessary power consumption but also a misreading problem, a fatal obstacle in memory operation. To fabricate a fully functional flexible memory and prevent these unwanted effects, we integrated high performance flexible single crystal silicon transistors with an amorphous titanium oxide (a-TiO2) based memristor to control the logic state of memory. The $8{\times}8$ NOR type 1T-1M RRAM demonstrated the first random access memory operation on flexible substrates by controlling each memory unit cell independently. The second part of the seminar will discuss the flexible GaN LED on LCP substrates for implantable biosensor. Inorganic III-V light emitting diodes (LEDs) have superior characteristics, such as long-term stability, high efficiency, and strong brightness compared to conventional incandescent lamps and OLED. However, due to the brittle property of bulk inorganic semiconductor materials, III-V LED limits its applications in the field of high performance flexible electronics. This seminar introduces the first flexible and implantable GaN LED on plastic substrates that is transferred from bulk GaN on Si substrates. The superb properties of the flexible GaN thin film in terms of its wide band gap and high efficiency enable the dramatic extension of not only consumer electronic applications but also the biosensing scale. The flexible white LEDs are demonstrated for the feasibility of using a white light source for future flexible BLU devices. Finally a water-resist and a biocompatible PTFE-coated flexible LED biosensor can detect PSA at a detection limit of 1 ng/mL. These results show that the nitride-based flexible LED can be used as the future flexible display technology and a type of implantable LED biosensor for a therapy tool. The final part of this seminar will introduce a highly efficient and printable BaTiO3 thin film nanogenerator on plastic substrates. Energy harvesting technologies converting external biomechanical energy sources (such as heart beat, blood flow, muscle stretching and animal movements) into electrical energy is recently a highly demanding issue in the materials science community. Herein, we describe procedure suitable for generating and printing a lead-free microstructured BaTiO3 thin film nanogenerator on plastic substrates to overcome limitations appeared in conventional flexible ferroelectric devices. Flexible BaTiO3 thin film nanogenerator was fabricated and the piezoelectric properties and mechanically stability of ferroelectric devices were characterized. From the results, we demonstrate the highly efficient and stable performance of BaTiO3 thin film nanogenerator.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.67-67
• /
• 2012

Graphene, two-dimensional one-atom-thick planar sheet of carbon atoms densely packed in a honeycomb crystal lattice, exhibits fascinating electrical properties, such as a linear energy dispersion relation and high mobility in addition to a wide-range optical absorption and high thermal conductivity. Graphene's outstanding tensile strength allows graphene-based electronic and photonic devices to be flexible, bendable, or even stretchable. Recently many groups have reported high performance electronic and optoelectronic devices based on graphene materials, i.e. field-effect transistors, gas sensors, nonvolatile memory devices, and plasmonic waveguides, in which versatile properties of graphene materials have been incorporated into a flexible electronic or optoelectronic platform. However, there are several fundamental or technological hurdles to be overcome in real applications of graphene in electronics and optoelectronics. In this tutorial we will present a short introduction to the basic material properties and recent progresses in applications of graphene to electronics and optoelectronics and discuss future outlook of graphene-based devices.