Changsoo Han

A transparent heater is produced from single-walled carbon nanotubes (SWCNTs) with a high thermal conductivity. A transparent conducting SWCNT film is fabricated on glass or polymer substrates by using a vacuum infiltration method. SWCNT films with a transparency of 65–97 % and a sheet resistance of 230–3500 Ω square–1 are demonstated. These films are good candidates for many applications that require transparent film heaters.

Highly efficient human skin systems transmit fast adaptive (FA) and slow adaptive (SA) pulses selectively or consolidatively to the brain for a variety of external stimuli. The integrated analysis of these signals determines how humans perceive external physical stimuli. Here, a self-powered mechanoreceptor sensor based on an artificial ion-channel system combined with a piezoelectric film is presented, which can simultaneously implement FA and SA pulses like human skin. This device detects stim

The irreversible photoenhancement of a quantum dot (QD) nanocomposite is demonstrated using UV photo-annealing. The QD nanocomposite consists of a mixture of thermally curable polymer and a QD, which is synthesized as a core/multishell nanocrystal, CdSe/CdS/CdZnS/ZnS. Exposure under 365-nm UV illumination for 30 min at 70 W surprisingly reveals that the photoluminescence of the QD nanocomposite increases 1.8 times.

Here, we report highly transparent and flexible AgNW/SWCNT hybrid networks on PET substrates combined with plasmonic welding for securing ultrahigh stability in mechanical and electrical properties under severe bending. Plasmonic welding produces local heating and welding at the junction of AgNWs and leads strong adhesion between AgNW and SWCNT as well as between hybrid structure and substrate. The initial sheet resistance of plasmon treated AgNW/SWCNT hybrid film was 26 Ω sq(-1), with >90% opti

Abstract The human cutaneous sensory organ is a highly evolved biosensor that is efficient, sensitive, selective, and adaptable. Recently, with the development of various materials and structures inspired by sensory organs, artificial cutaneous sensors have been widely studied. In this study, the acquisition of biophysical signals is demonstrated at one point on the body using a wearable all‐gel‐integrated multimodal sensor composed of four element sensors, inspired by the slow/rapid adapting fu

We report successive and large-scale synthesis of InP/ZnS core/shell nanocrystal quantum dots (QDs) using a customized hybrid flow reactor, which is based on serial combination of a batch-type mixer and a flow-type furnace. InP cores and InP/ZnS core/shell QDs were successively synthesized in the hybrid reactor in a simple one-step process. In this reactor, the flow rate of the solutions was typically 1 ml min(-1), 100 times larger than that of conventional microfluidic reactors. In order to syn

The direct transfer method of large area monolayer CVD graphene from Cu foil to various substrates such as PET, PDMS, and glass is developed using mechano-electro-thermal forces based on ultraconformal contact without any metal etching process or additional carrier layers in a solid-state process. Transferred graphene presents both excellent quality (with no residues, few defects, or no folding) and remarkable mechanical and electrical stability.

Highly pure metallic single-walled carbon nanotubes were continuously extracted from a mixture of semiconducting and metallic species using a nondestructive, scalable method. Two laminar streams were generated in an H-shaped microfluidic channel with two inlets and two outlets. The flow conditions were carefully controlled to minimize diffusive and convective transport across the boundary between the two flows. Dielectrophoretic force from the embedded electrode at the junction extracted metalli

We report ambivalent rejection behavior of a graphene oxide membrane (GOM) having a reduced interlayer spacing. Ultrathin GOMs having a thickness of 50 nm were fabricated using a vacuum filtration method followed by subjecting the samples to thermal reduction at 162 °C. The interlayer spacing of GOMs was reduced by 1 Å on thermal reduction as compared with that of the natural GOMs. The rejection rate with dye molecules was tested using dyes having three different types of charges in a dead-end f

We investigate thermal behavior of transparent film heaters (TFH) made of single-walled carbon nanotubes. We fabricate the TFH by using the spray coating method. We studied the temperature dependence of the electrical resistance of the TFH in terms of Joule and external heating in various gas environments. Test results show that the effect of the electrical current through the TFH on the temperature dependence of the electrical resistance is not important and that the humidity and the degree of

Novel hydrogel shows highly elastic, conductive, tough, transparent, humidity-resistive property which is useful for the wearable strain-sensing device.

Colloidal III-V semiconductor nanocrystal quantum dots [NQDs] have attracted interest because they have reduced toxicity compared with II-VI compounds. However, the study and application of III-V semiconductor nanocrystals are limited by difficulties in their synthesis. In particular, it is difficult to control nucleation because the molecular bonds in III-V semiconductors are highly covalent. A synthetic approach of InP NQDs was presented using newly synthesized organometallic phosphorus [P] pr

Biological ion channels have led to much inspiration because of their unique and exquisite operational functions in living cells. Specifically, their extreme and dynamic sensing abilities can be realized by the combination of receptors and nanopores coupled together to construct an ion channel system. In the current study, we demonstrated that artificial ion channel pressure sensors inspired by nature for detecting pressure are highly sensitive and patchable. Our ion channel pressure sensors bas