202 results match your criteria: "Korea institute of Machinery and Materials KIMM[Affiliation]"

Microfluidic device for one-step detection of breast cancer-derived exosomal mRNA in blood using signal-amplifiable 3D nanostructure.

Biosens Bioelectron

February 2022

Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea; Department of Nanobiotechnology, KRIBB School of Biotechnology, University of Science and Technology, 125 Gwahak-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea. Electronic address:

Metastasis attributed to approximately 90% of cancer-related deaths; hence, the detection of metastatic tumor-derived components in the blood assists in determining cancer recurrence and patient survival. Microfluidic-based sensors facilitate analysis of small fluid volumes and represent an accurate, rapid, and user-friendly method of field diagnoses. In this study, we have developed a microfluidic chip-based exosomal mRNA sensor (exoNA-sensing chip) for the one-step detection of exosomal ERBB2 in the blood by integrating a microfluidic chip and 3D-nanostructured hydrogels.

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The conventional tissue biopsy method yields isolated snapshots of a narrow region. Therefore, it cannot facilitate comprehensive disease characterization and monitoring. Recently, the detection of tumor-derived components in body fluids─a practice known as liquid biopsy─has attracted increased attention from the biochemical research and clinical application viewpoints.

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Force uniformity control for large-area roll-to-roll process.

Rev Sci Instrum

October 2021

School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Republic of Korea.

Demand for high throughput manufacturing has recently increased in various fields, such as electronics, photonics, optical devices, and energy. Moreover, flexible electronic devices are indispensable in applications such as touch screens, transparent conductive electrodes, transparent film heaters, organic photovoltaics, organic light-emitting diodes, and battery. For these applications, a large-area roll-to-roll (R2R) process is a promising method for producing with high throughput.

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Recently, three-dimensional electronics (3DE) is attracting huge interest owing to the increasing demands for seamless integration of electronic systems on 3D curvilinear surfaces. However, it is still challenging to fabricate 3DE with high customizability, conformability, and stretchability. Here, we present a fabrication method of 3DE based on predistorted pattern generation and thermoforming.

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IoT device fabrication using roll-to-roll printing process.

Sci Rep

October 2021

Department of Printed Electronics, Korea Institute of Machinery and Materials (KIMM), 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon, 34103, Republic of Korea.

With the development of technology, wireless and IoT devices are increasingly used from daily life to industry, placing demands on rapid and efficient manufacturing processes. This study demonstrates the fabrication of an IoT device using a roll-to-roll printing process, which could shorten the device fabrication time and reduce the cost of mass production. Here, the fabricated IoT device is designed to acquire data through the sensor, process the data, and communicate with end-user devices via Bluetooth communication.

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Makers of point-of-care devices and wearable diagnostics prefer flexible electrodes over conventional electrodes. In this study, a flexible electrode platform is introduced with a WS /graphene heterostructure on polyimide (WGP) for the concurrent and selective determination of dopamine and serotonin. The WGP is fabricated directly via plasma-enhanced chemical vapor deposition (PECVD) at 150 °C on a flexible polyimide substrate.

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In this study, we report a method to fabricate molds and flexible stamps with 2D photonic crystal structures. This includes self-assembly of polystyrene particles into monolayer, oxygen reactive ion etching, thin film (chromium (Cr)) deposition, and polydimethylsiloxane replication. By tuning the thickness of Cr layer, reusable master molds with nano bumps or nano concaves could be prepared selectively.

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Article Synopsis
  • - The study investigates a new method to create strong self-adhesion in flexible and transparent conductive films made from metal nanowires using flashlight annealing, which rapidly modifies the material characteristics.
  • - The process involves interlocking nanowires through hot pressing, then applying flashlight irradiation to trigger interdiffusion, melting of surface polymers, and morphological changes, enhancing the film's surface area.
  • - The resulting self-adhesive film demonstrates strong interfacial interactions, making it suitable for connecting light-emitting diode chips and has potential applications in defogging windows and transparent organic light-emitting diodes.
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Surface-enhanced Raman spectroscopy (SERS) detection in microfluidics is an interesting topic because of its high sensitivity, miniaturization, and ability to perform online detection. However, the difficulties in generating SERS-based microfluidic devices with uniform signal reproducibility and high sensitivity have hindered their widespread application. In addition, the recyclability of the SERS-based microfluidic devices can contribute to their broad commercialization, but the possible contamination in the detection area and cumbersome cleaning procedures remain a challenge.

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Photocatalytic exoskeleton: Chitin nanofiber for retrievable and sustainable TiO carriers for the decomposition of various pollutants.

Carbohydr Polym

November 2021

Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Chengam-ro, Nam-gu, Pohang 37673, Republic of Korea; Institute for Convergence Research and Education in Advanced Technology, Yonsei University International Campus I-CREATE, Incheon 21983, Republic of Korea. Electronic address:

Loading a photocatalytic TiO to organic carriers has been desired for volumetric TiO incorporation, facile retrieval, and sustainable utilization. Traditionally, suspended TiO nanoparticles or its thin film on two-dimensional substrate are popularly fabricated for pollutants decomposition without carriers; due to poor thermomechanical properties of the organic carriers. Herein, a combination of the chitin nanofiber carrier and atomic layer deposition proves relevance for formation of anatase TiO thin layer so that photocatalytic decomposition in three-dimensional surface.

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Many conventional micropatterning and nanopatterning techniques employ toxic chemicals, rendering them nonbiocompatible and unsuited for biodevice production. Herein the formation of water bridges on the surface of hyaluronic acid (HA) films is exploited to develop a transfer-based nanopatterning method applicable to diverse structures and materials. The HA film surface, made deformable via water bridge generation, is brought into contact with a functional material and subjected to thermal treatment, which results in film shrinkage, allowing a robust pattern transfer.

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Pseudocapacitive materials encapsulated in conductive carbon matrix are of paramount importance to develop energy storage devices with high performance and long lifespan. Here, via simple laser-scribing, the Mn-based metal-organic framework [EG-MOF-74(Mn)] is transformed into pseudocapacitive hybrid MnO/Mn C encapsulated in highly conductive graphitic carbon. It is revealed that the rapid carbothermic reduction of MnO (C + MnO → C' + Mn C + CO) leads to the formation of the intermediate pseudocapacitive MnO/Mn C and the concurrent catalytic graphitization of disordered carbon.

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Microwave absorbers using conductive ink are generally fabricated by printing an array pattern on a substrate to generate electromagnetic fields. However, screen printing processes are difficult to vary the sheet resistance values for different regions of the pattern on the same layer, because the printing process deposits materials at the same height over the entire surface of substrate. In this study, a promising manufacturing process was suggested for engraved resistive double square loop arrays with ultra-wide bandwidth microwave.

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Bio-plotted hydrogel scaffold with core and sheath strand-enhancing mechanical and biological properties for tissue regeneration.

Colloids Surf B Biointerfaces

September 2021

Department of Nature-Inspired System and Application, Korea Institute of Machinery and Materials (KIMM), Daejeon, 34103, Republic of Korea. Electronic address:

Three-dimensional bio-plotted scaffolds constructed from encapsulated biomaterials or so-called "bio-inks" have received much attention for tissue regeneration applications, as advances in this technology have enabled more precise control over the scaffold structure. As a base material of bio-ink, sodium alginate (SA) has been used extensively because it provides suitable biocompatibility and printability in terms of creating a biomimetic environment for cell growth, even though it has limited cell-binding moiety and relatively weak mechanical properties. To improve the mechanical and biological properties of SA, herein, we introduce a strategy using hydroxyapatite (HA) nanoparticles and a core/sheath plotting (CSP) process.

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Rapid and simple single-chamber nucleic acid detection system prepared through nature-inspired surface engineering.

Theranostics

August 2021

Department of Emerging Materials Science, DGIST, Daegu, 42988, Republic of Korea.

Nucleic acid (NA)-based diagnostics enable a rapid response to various diseases, but current techniques often require multiple labor-intensive steps, which is a major obstacle to successful translation to a clinical setting. We report on a surface-engineered single-chamber device for NA extraction and amplification without sample transfer. Our system has two reaction sites: a NA extraction chamber whose surface is patterned with micropillars and a reaction chamber filled with reagents for polymerase-based NA amplification.

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Fog Collection Based on Secondary Electrohydrodynamic-Induced Hybrid Structures with Anisotropic Hydrophilicity.

ACS Appl Mater Interfaces

June 2021

Department of Physics, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea.

The outcomes of the study of plant surfaces, such as rice leaves or bamboo leaves, have led to extensive efforts being devoted to fabricating anisotropic arrays of micro/nanoscale features for exploring anisotropic droplet spreading. Nonetheless, precise engineering of the density and continuity of three-phase contact lines for anisotropic wetting remains a significant challenge without resorting to chemical modifications and costly procedures. In this work, we investigated secondary electrohydrodynamic instability in polymer films for producing secondary nanosized patterns between the micrometer-sized grooves by controlling the timescale parameter, 1/τ (>10 s).

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Selective colorimetric urine glucose detection by paper sensor functionalized with polyaniline nanoparticles and cell membrane.

Anal Chim Acta

May 2021

Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, South Korea; Interdisciplinary Graduate Program for Artificial Intelligence Smart Convergence Technology, Korea University, Sejong 30019, South Korea. Electronic address:

For the diabetes diagnosis, noninvasive methods are preferred to invasive methods; urine glucose measurement is an example of a noninvasive method. However, conventional noninvasive methods for urine glucose measurement are not intuitive. Furthermore, such methods exhibit low selectivity because they can detect interfering molecules in addition to glucose.

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Bio-ink properties have been extensively studied for use in the three-dimensional (3D) bio-printing process for tissue engineering applications. In this study, we developed a method to synthesize bio-ink using hyaluronic acid (HA) and sodium alginate (SA) without employing the chemical crosslinking agents of HA to 30% (/). Furthermore, we evaluated the properties of the obtained bio-inks to gauge their suitability in bio-printing, primarily focusing on their viscosity, printability, and shrinkage properties.

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Strategically Controlled Flash Irradiation on Silicon Anode for Enhancing Cycling Stability and Rate Capability toward High-Performance Lithium-Ion Batteries.

ACS Appl Mater Interfaces

April 2021

Department of Printed Electronics, Nano-Convergence Manufacturing Systems Research Division, Korea Institute of Machinery and Materials(KIMM), 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 34103, Republic of Korea.

Si has attracted considerable interest as a promising anode material for next-generation Li-ion batteries owing to its outstanding specific capacity. However, the commercialization of Si anodes has been consistently limited by severe instabilities originating from their significant volume change (approximately 300%) during the charge-discharge process. Herein, we introduce an ultrafast processing strategy of controlled multi-pulse flash irradiation for stabilizing the Si anode by modifying its physical properties in a spatially stratified manner.

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After the WHO designated COVID-19 a global pandemic, face masks have become a precious commodity worldwide. However, uncertainty remains around several details regarding face masks, including the potential for transmission of bioaerosols depending on the type of mask and secondary spread by face masks. Thus, understanding the interplay between face mask structure and harmful bioaerosols is essential for protecting public health.

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Green Picosecond Laser Machining of Thermoset and Thermoplastic Carbon Fiber Reinforced Polymers.

Micromachines (Basel)

February 2021

Laser Industrial Technology Research Group, Korea Institute of Machinery and Materials (KIMM), 48, Mieumsandan 5-ro 41beon-gil, Busan 46744, Korea.

There has been an increase in demand for the development of lightweight and high-strength materials for applications in the transportation industry. Carbon fiber reinforced polymer (CFRP) is known as one of the most promising materials owing to its high strength-to-weight ratio. To apply CFRP in the automotive industry, various machining technologies have been reported because it is difficult to machine.

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N-type bismuth telluride (BiTe) thin films were prepared on an aluminum nitride (AlN)-coated stainless steel foil substrate to obtain optimal thermoelectric performance. The thermal co-evaporation method was adopted so that we could vary the thin film composition, enabling us to investigate the relationship between the film composition, microstructure, crystal preferred orientation and thermoelectric properties. The influence of the substrate temperature was also investigated by synthesizing two sets of thin film samples; in one set the substrate was kept at room temperature (RT) while in the other set the substrate was maintained at a high temperature, of 300 °C, during deposition.

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Flexible resonant acoustic sensors have attracted substantial attention as an essential component for intuitive human-machine interaction (HMI) in the future voice user interface (VUI). Several researches have been reported by mimicking the basilar membrane but still have dimensional drawback due to limitation of controlling a multifrequency band and broadening resonant spectrum for full-cover phonetic frequencies. Here, highly sensitive piezoelectric mobile acoustic sensor (PMAS) is demonstrated by exploiting an ultrathin membrane for biomimetic frequency band control.

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The conventional synthesis of two-dimensional (2D) transition metal dichalcogenide (TMDC) heterostructures is low yielding and lack the heterojunction interface quality. The chemical vapor deposition (CVD) techniques have achieved high-quality heterostructure interfaces but require a high synthesis temperature (>600 °C) and have a low yield of heterostructures. Therefore, the large scale and high interface quality of TMDC heterojunctions using low-temperature synthesis methods are in demand.

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Reactive Self-Collision Avoidance for a Differentially Driven Mobile Manipulator.

Sensors (Basel)

January 2021

Graduate School of Convergence Science and Technology, Seoul National University, Seoul 08826, Korea.

This paper introduces a reactive self-collision avoidance algorithm for differentially driven mobile manipulators. The proposed method mainly focuses on self-collision between a manipulator and the mobile robot. We introduce the concept of a distance buffer border (DBB), which is a 3D curved surface enclosing a buffer region of the mobile robot.

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