김하늘 교수

Abstract The ability to image pressure distribution over complex three-dimensional surfaces would significantly augment the potential applications of electronic skin. However, existing methods show poor spatial and temporal fidelity due to their limited pixel density, low sensitivity, or low conformability. Here, we report an ultraflexible and transparent electroluminescent skin that autonomously displays super-resolution images of pressure distribution in real time. The device comprises a trans

Liquid metal is being regarded as a promising material for soft electronics owing to its distinct combination of high electrical conductivity comparable to that of metals and exceptional deformability derived from its liquid state. However, the applicability of liquid metal is still limited due to the difficulty in simultaneously achieving its mechanical stability and initial conductivity. Furthermore, reliable and rapid patterning of stable liquid metal directly on various soft substrates at hi

A simple yet effective object descriptor for visual tracking is proposed in this paper. We first decompose the bounding box of a target object into multiple patches, which are described by color and gradient histograms. Then, we concatenate the features of the spatially ordered patches to represent the object appearance. Moreover, to alleviate the impacts of background information possibly included in the bounding box, we determine patch weights using random walk with restart (RWR) simulations.

Abstract We report on the polarized Raman scattering results of vertically stacked few‐layer MoS 2 grown by chemical vapor deposition. Results of monolayer MoS 2 showed that the polarization‐angle‐resolved intensity profiles of both out‐of‐plane A 1g and in‐plane phonon modes followed the Raman polarization selection rules. In contrast, the polarization‐angle dependence of the phonon intensity in the multilayer region showed a deviation from the polarization selection rules, whereas that of the

Capillary rise is important in many aspects of physical phenomena from transport in porous media to biotechnology. It is typically described by the Lucas-Washburn-Rideal equation (LWRE), but discrepancy between some experiments and the model still remains elusive. In this paper, we show that the discrepancy is simply from the contact angle change during the capillary rise with no help of any specific models, such as dynamic contact angle (DCA) models. To demonstrate this, we directly measure the

Efficient action recognition has become crucial to extend the success of action recognition to many real-world applications. Contrary to most existing methods, which mainly focus on selecting salient frames to reduce the computation cost, we focus more on making the most of the selected frames. To this end, we employ two networks of different capabilities that operate in tandem to efficiently recognize actions. Given a video, the lighter network processes more frames while the heavier one only p

Abstract The charge transfer phenomenon is identified to be a major factor determining exciton and trion characteristics of atomically thin MoS 2 layers in various stacking configurations. We report photoluminescence (PL) from CVD-grown layered MoS 2 in the presence of a skewed or a deformed triangular-shaped monolayer/bilayer (1L/2L) lateral interface. Integrated PL mapping images over the 1L and 2L MoS 2 regions revealed that the neutral exciton emission was significantly enhanced and exhibite

We report simultaneous Raman scattering and photoluminescence (PL) mapping results to study the strain and doping effects of chemical treatment with bis(trifluoromethane) sulfonimide (TFSI) on the optical phonon, exciton, and trion characteristics of a vertically stacked monolayer–bilayer (1L–2L) MoS2 structure. Correlation analysis between the E′ and A1′ phonon energies revealed that tensile strain developed in the TFSI-treated MoS2 mainly by the filling of sulfur vacancies: 0.13% and 0.10% for

Two-dimensional semiconductor heterostructures provide significant research potential for electronic and optoelectronic applications because of their scaled thickness, pristine heterostructure interface, and ultrafast carrier transport. Herein, we report a dual-channel field-effect transistor based on n-type WS 2 and p-type WSe 2 layered heterostructure using multilayered graphene as electrodes to enable electron-dominated ambipolar electrical transport. WS 2 exhibits mobility of 20 cm 2 V –1 s

Soft pressure sensors play key roles as input devices of electronic skin (E-skin) to imitate real human skin. For efficient data acquisition according to stimulus types such as detailed pressure images or macroscopic strength of stimuli, soft pressure sensors can have variable spatial resolution, just like the uneven spatial distribution of pressure-sensing receptors on the human body. However, previous methods on soft pressure sensors cannot achieve such tunability of spatial resolution because

Abstract A graphene-MoS 2 (GM) heterostructure based diode is fabricated using asymmetric contacts to MoS 2 , as well as an asymmetric top gate (ATG). The GM diode exhibits a rectification ratio of 5 from asymmetric contacts, which is improved to 10 5 after the incorporation of an ATG. This improvement is attributed to the asymmetric modulation of carrier concentration and effective Schottky barrier height (SBH) by the ATG during forward and reverse bias. This is further confirmed from the tempe

How to make an online tracking model effectively adapt to newly appearing objects and object disappearance as well as appearance variations of target objects from few examples is an essential issue in multiple object tracking (MOT). Learning target appearances from few examples is a few-shot classification problem, while identifications of newly appearing objects and object disappearance has the aspect of open-set classification. In this work, we regard online MOT as open-set few-show classifica

A two-dimensional (2D) atomic crystalline transition metal dichalcogenides has shown immense features, aiming for future nanoelectronic devices comparable to conventional silicon (Si). 2D molybdenum ditelluride (MoTe2) has a small bandgap, appears close to that of Si, and is more favorable than other typical 2D semiconductors. In this study, we demonstrate laser-induced p-type doping in a selective region of n-type semiconducting MoTe2 field effect transistors (FET) with an advance in using the