Micro Light‐Emitting Diodes for Display and Flexible Biomedical Applications

Abstract

Inorganic-based micro light-emitting diodes (µLEDs) have witnessed significant improvements in terms of display and biomedical applications, which can shift the paradigm of future optoelectronic systems. In particular, µLED displays are on the verge of becoming the next big interface platform for visual communications, expanding to various internet of things and wearable/bioapplications. Novel µLED concepts need to be upgraded to be able to satisfy their potential optoelectric applications, such as virtual reality, smart watches, and medical sensors for individual computing in this hyperconnected society. Here, representative progresses in the field of flexible µLEDs are reviewed with regard to device structures, massive µLED transfers, methods for performance enhancement, and applications.

Numerical and Experimental Study on the Heat Dissipation Performance of a Novel System

“…It is seen in Figure 15 that the component surface temperature increased as the cloudiness coefficient increased. According to Equations (12) and (13), the higher the cloudiness coefficient, the greater the sky temperature, and the ability of the radiative plate to radiate into the sky is weakened, so the higher the surface temperature of the equipment is. However, the surface temperature of the component increased slightly, e.g., the cloudy weather (C a = 9) was 0.8 • C lower than the sunny weather (C a = 1), mainly because the net radiation heat transfer coefficient was lower.…”

“…Therefore, heat dissipation technology has become the key to achieving long-life and high-reliability performance [5]. For this purpose, many effective methods have been implemented in forced convection cooling techniques, such as heat sinks cooled by air or liquid [6][7][8], microchannel pipes [9], and new materials and new technology [10][11][12]. However, the conventional air-cooled cooling systems are often inadequate to remove excessive heat from electronic components because of narrow heat dissipation space [13].…”

Electronic Component Mounting for Durable E-Textiles: Direct Soldering of Components onto Textile-Based Deeply Permeated Conductive Patterns

“…In recent years, electronic textiles (e-textiles) have attracted significant research attention with respect to the development of new biological information monitoring systems [1][2][3][4][5][6], human interface systems [7,8], and fashions [9,10], among other schemes [11][12][13][14][15][16][17][18]. At present, only conductive tracks and pads and several types of sensors can be formed on a textile by weaving, knitting, and stitching of conductive yarns on the textile [9,[19][20][21], or by printing of conductive inks on the textiles [3,22,23].…”

Optimization on Adhesive Stamp Mass-Transfer of Micro-LEDs With Support Vector Machine Model

“…In recent years, micro light-emitting diode (micro-LED) has attracted a lot of attentions for its vast potential applications in various fields, such as micro-display [1]- [3], visible light communication [4]- [7], biomedical [8] and wearable devices [9]. Compared to LCD (liquid crystal display) and OLED (organic light-emitting diode) display, micro-LED display is advantageous for some unique features, including excellent light properties (e.g., contrast, hue and brightness), fast response time, high power efficiency and long lifetime [10]- [13].…”

“…A variety of mass-transfer techniques have been proposed to assemble Micro-LEDs, such as laser-Assisted mass transfer [14]- [17], fluidic self-assembly [18], [19], electrostatic mass transfer [20]- [22], micro vacuumbased transfer [8], elastomeric stamp or roll-based mass transfer [23], [24] and the adhesive stamp mass transfer adopted in this work [25]- [28]. Laser-assisted mass transfer is developed for selective micro-LEDs printing upon laser irradiation on the light-reactive layers [14]- [17].…”