scholarly journals Fully solution processed liquid metal features as highly conductive and ultrastretchable conductors

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Hangyu Zhu ◽  
Shaolei Wang ◽  
Menghu Zhang ◽  
Tingyu Li ◽  
Gaohua Hu ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Heterogeneous Integration ◽  
Stretchable Electronics ◽  
Ambient Conditions ◽  
Light Emitting ◽  
Led Array ◽  
Mechanical Durability ◽  
Metal Interconnects

AbstractLiquid metal represents a highly conductive and inherently deformable conductor for the development of stretchable electronics. The widespread implementations of liquid metal towards functional sensors and circuits are currently hindered by the lack of a facile and scalable patterning approach. In this study, we report a fully solution-based process to generate patterned features of the liquid metal conductor. The entire process is carried out under ambient conditions and is generally compatible with various elastomeric substrates. The as-prepared liquid metal feature exhibits high resolution (100 μm), excellent electrical conductivity (4.15 × 104S cm−1), ultrahigh stretchability (1000% tensile strain), and mechanical durability. The practical suitability is demonstrated by the heterogeneous integration of light-emitting diode (LED) chips with liquid metal interconnects for a stretchable and wearable LED array. The solution-based technique reported here is the enabler for the facile patterning of liquid metal features at low cost, which may find a broad range of applications in emerging fields of epidermal sensors, wearable heaters, advanced prosthetics, and soft robotics.

scholarly journals Foldable and washable textile-based OLEDs with a multi-functional near-room-temperature encapsulation layer for smart e-textiles

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
So Yeong Jeong ◽  
Hye Rin Shim ◽  
Yunha Na ◽  
Ki Suk Kang ◽  
Yongmin Jeon ◽  
...  
Keyword(s):  
Room Temperature ◽  
Wearable Electronics ◽  
Ambient Conditions ◽  
Light Emitting ◽  
Stable Operating ◽  
Mechanical Durability ◽  
Potential Applications ◽  
Wearable Electronic ◽  
Data Signal ◽  
Wearable Electronic Devices

AbstractWearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited a stable operating lifetime under ambient conditions, enough mechanical durability to endure the deformation by the movement of humans, and washability for maintaining its optoelectronic properties even in water condition such as rain, sweat, or washing. In this study, the main technology used to realize this textile-based OLED was multi-functional near-room-temperature encapsulation. The outstanding impermeability of TiO2 film deposited at near-room-temperature was demonstrated. The internal residual stress in the encapsulation layer was controlled, and the device was capped by highly cross-linked hydrophobic polymer film, providing a highly impermeable, mechanically flexible, and waterproof encapsulation.

Porphyrin doping of dichloride-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex for electroluminescence

2013 ◽  
Vol 17 (05) ◽  
pp. 351-358 ◽  
Author(s):  
Mohammad Janghouri ◽  
Ezeddin Mohajerani ◽  
Mostafa M. Amini ◽  
Naser Safari
Keyword(s):  
Molecular Orbital ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Energy Levels ◽  
Orbital Energy ◽  
Homogeneous Layer ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Fundamental Structure ◽  
Organic Light

A method for obtaining red emission from an organic-light emitting diode has been developed by dissolving red and yellow dyes in a common solvent and thermally evaporating the mixture in a single furnace. Dichlorido-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex ( Q2SnCl2 , Q = 5,7-dichloro-8-hydroxyquinoline) has been synthesized for using as a fluorescent material in organic light-emitting diodes (OLEDs). The electronic states HOMO (Highest Occupied Molecular Orbital)/LUMO (Lowest Occupied Molecular Orbital) energy levels explored by means of cyclic voltammetry measurements. A device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/ Q2SnCl2/Al (180nm) was fabricated and its electroluminescence performance at various thicknesses of light emitting layer (LEL) of Q2SnCl2 is reported. By following this step, an optimal thickness for the doping effect was also identified and explained. Finally a device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/meso-tetraphenylporphyrin (TPP): Q2SnCl2 (75nm)/ Al (180nm) was fabricated and its electroluminescence performance at various concentrations of dye has been investigated. It is shown that this new method is promising candidate for fabrication of low cost OLEDs at more homogeneous layer.

Miniaturized UV-LED Array Chip Photochemical Vapor Generator Coupled with Point Discharge Optical Emission Spectrometer for Determination of Trace Selenium

2021 ◽  
Author(s):  
Mengtian Li ◽  
Yi Luo ◽  
Zhirong Zou ◽  
Fujian Xu ◽  
Xiaoming Jiang ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Optical Emission ◽  
Nano Tio2 ◽  
Light Emitting ◽  
Uv Led ◽  
Led Array ◽  
Point Discharge ◽  
Photochemical Vapor Generation ◽  
Optical Emission Spectrometer

An ultraviolet light emitting diode (UV-LED) array chip as irradiation source for nano-TiO2 catalyzed photochemical vapor generation (PCVG) was combined with a hollow electrode point discharge microplasma optical emission spectrometer...

Low Cost Cooling Device for High Power LED Lamps

2020 ◽  
Author(s):  
Pamela Martinez-Vega ◽  
Araceli Lopez-Badillo ◽  
J. Luis Luviano-Ortiz ◽  
Abel Hernandez-Guerrero ◽  
Jaime G. Cervantes
Keyword(s):  
Reference Model ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Cost Effective ◽  
Heat Sinks ◽  
Modern World ◽  
Type Model ◽  
Light Emitting

Abstract The modern world progressively demands more energy; according to forecasts energy consumption will grow at an average annual rate of 3 percent. Therefore, it is necessary to purchase products or devices that are efficient and environmentally friendly. Technology in LED (Light Emitting Diode) lighting is presented as an alternative to energy saving, since LEDs have proven to be extremely efficient, have a long service life and their cost-effective ratio is very good. However, the heat emitted by the LED chip must be dissipated effectively, since the overheating of the chip reduces the efficiency and lifetime of the lamp. Therefore, heat sinks that are reliable, efficient and inexpensive should be designed and built. The present work proposes new designs for heat sinks in LED lamps, some of the models in the design of the fins refer to the Fibonacci series. The models proposed in the present work that have a significant advantage are the Type 1E Model (5.2% mass savings and better thermal efficiency of 8.33%), GR Type 1 Model (3.12% lighter and 3.33% more efficient) and the GRL Type Model (4. 51% mass savings and 5.55% thermally more efficient) compared to the Type 2 Reference Model proposed by Jang et al. [12].

scholarly journals Preparation of Organic Light-Emitting Diode Using Coal Tar Pitch, a Low-Cost Material, for Printable Devices

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e62903 ◽  
Author(s):  
Miki Yamaoka ◽  
Shun-suke Asami ◽  
Nayuta Funaki ◽  
Sho Kimura ◽  
Liao Yingjie ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Low Cost ◽  
Coal Tar ◽  
Coal Tar Pitch ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light

Thermal Performance of a Light Emitting Diode Light Engine for a Multipurpose Automotive Exterior Lighting System With Competing Board Technologies

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Umut Zeynep Uras ◽  
Mehmet Arık ◽  
Enes Tamdoğan
Keyword(s):  
Thermal Performance ◽  
Computational Models ◽  
Printed Circuit Boards ◽  
Light Emitting Diode ◽  
Ambient Conditions ◽  
Vapor Chamber ◽  
Metal Core ◽  
Light Emitting ◽  
Lighting Systems ◽  
Light Engine

In recent years, light emitting diodes (LEDs) have become an attractive technology for general and automotive illumination systems replacing old-fashioned incandescent and halogen systems. LEDs are preferable for automobile lighting applications due to its numerous advantages such as low power consumption and precise optical control. Although these solid state lighting (SSL) products offer unique advantages, thermal management is one of the main issues due to severe ambient conditions and compact volume. Conventionally, tightly packaged double-sided FR4-based printed circuit boards (PCBs) are utilized for both driver electronic components and LEDs. In fact, this approach will be a leading trend for advanced internet of things applications embedded LED systems in the near future. Therefore, automotive lighting systems are already facing with tight-packaging issues. To evaluate thermal issues, a hybrid study of experimental and computational models is developed to determine the local temperature distribution on both sides of a three-purpose automotive light engine for three different PCB approaches having different materials but the same geometry. Both results showed that FR4 PCB has a temperature gradient (TMaxBoard to TAmbient) of over 63 °C. Moreover, a number of local hotspots occurred over FR4 PCB due to low thermal conductivity. Later, a metal core PCB is investigated to abate local hot spots. A further study has been performed with an advanced heat spreader board based on vapor chamber technology. Results showed that a thermal enhancement of 7.4% and 25.8% over Al metal core and FR4-based boards with the advanced vapor chamber substrate is observed. In addition to superior thermal performance, a significant amount of lumen extraction in excess of 15% is measured, and a higher reliability rate is expected.

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