Jang‐Kun Song

Triboelectric nanogenerators (TENGs) can be incorporated into modern electronic devices requiring sustainable, renewable, and reliable microscale energy sources. We report the first use of human hair, which is known to be a highly triboelectric material, for the fabrication of biobased TENGs. Ethanolic NaOH was used to dissolve hair, and two simple fabrication techniques, bar- and spin-coating methods, were used to prepare hair-based films on electrode substrates. The dissolved hair paste has so

Abstract A modified DCC (Dynamic Capacitance Compensation), DCCII has been developed for the fast response time performance in PVA TFT‐LCD TVs. DCCII applies a pre‐tilt voltage to addressed pixels during the previous frame in addition to an overshoot voltage. In result, the response time less than 8 msec, has been obtained for all moving images through the DCCII technique.

Liquid-solid contact electrification is a useful mechanism to harvest wasted micromechanical energy. In this study, we investigate how the surface properties of a solid substrate affect contact electrification efficiency. Substrate surfaces were modified from hydrophilic to hydrophobic by changing the density of self-assembled monolayers (SAMs) on a SiO2 surface. A substrate with a partially-covered SAM exhibited superior performance. The partially-covered SAM substrate is hydrophobic enough to

The surface of self-constructed molecular density modulation (SDM) exhibits a wide range of liquid crystal alignment capabilities including planar, tilted, and homeotropic alignments, disclination-free uniform and heterogeneous alignments, and even spatially varying alignments through the single non-contact process. Alignment defects are eliminated by temporary lowering the frictional energy barrier via the open-boundary elastic stabilization (OES) treatment.

We demonstrate a novel structure for a quantum-dot light-emitting diode (QD-LED) with wide-range colour-tuneable pixels, fabricated via full solution processing. The proposed device has a symmetrical structure produced via stacking of an inverted-structure diode with a green QD emission layer (EML) and normal-structure diode with a red QD EML. It is an electron-only device; however, a charge generation layer in the middle of the device generates holes for the formation of excitons. Depending on

Here, we demonstrate excellent liquid crystal (LC) vertical alignment without using an alignment layer printing process by introducing octadecyltrichlorosilane (OTS) into the LC mixture. Further, we investigated the alignment mechanism by analysing the surfaces of the substrates. The optimum concentration of OTS was found to be about 0.03 wt%, which is 1/100 of that in the previously reported polyhedral oligomeric silsesquioxane (POSS)–LC system. Moreover, the OTS–LC system exhibited a more stab

Abstract Since optical vortex (OV) beams possess an additional degree of freedom, orbital angular momentum, the beams can be utilized to enhance signal modulation in optical communication technologies by mode division multiplexing and information encoding. In particular, tunable OV devices with wavelength adjustment and channel switching generate wide interest among researchers. This paper demonstrates tunable OV generator based on a grid‐patterned liquid crystal (GPLC) cell. The device, which i

Microfabrication of complex double emulsion droplets with controlled substructures, which resemble biological cells, is an important but a highly challenging subject. Here, a new approach is proposed based on laser-induced injection of water nanodroplets into a liquid crystal (LC) drop. In contrast to the conventional top-down microfluidic fabrication, this method employs a series of bottom-up strategies such as nanodroplet injection, spontaneous and assisted coalescence, elastically driven actu