Sungkyunkwan University

About: Sungkyunkwan University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Graphene. The organization has 28229 authors who have published 56428 publications receiving 1352733 citations. The organization is also known as: 성균관대학교.

Recent progress on patchy colloids and their self-assembly

Abstract: 'Patchy colloids' is a term that has been recently introduced to indicate specially engineered particles with directional interactions. Based on this concept, a 'bottom-up' process for fabricating functional materials and devices has been envisioned, which employs colloidal building blocks and mimics molecular bonding. This article reviews recent progress which has been made in the synthesis and self-assembly of patchy colloids and discusses future directions as well as unresolved challenges.

Development of Soft-Actuator-Based Wearable Tactile Display

Abstract: As a major human sensory function, the implementation of the tactile sensation for the human-machine interface has been one of the core research interests for long time. In this paper, an innovative tactile display device based on the soft actuator technology is presented. Using electroactive polymer for the construction of the tactile display device, it can provide stimulation on the human skin without any additional electromechanical transmission. Softness and flexibility of the device structure, ease of fabrication, possibility for miniaturization, and low cost for mass production are the representative benefits of the presented device. Especially, the device application is open to many different purposes since the flexible structure offers the excellent adaptability to any contour of the human body. To prove its feasibility, a wearable device that can fit to the distal part of the human finger is presented and its performance is evaluated, experimentally.

Oxygen-activated growth and bandgap tunability of large single-crystal bilayer graphene

Abstract: Large, bilayer graphene single crystals can be grown by oxygen-activated chemical vapour deposition. Bernal (AB)-stacked bilayer graphene (BLG) is a semiconductor whose bandgap can be tuned by a transverse electric field, making it a unique material for a number of electronic and photonic devices1,2,3. A scalable approach to synthesize high-quality BLG is therefore critical, which requires minimal crystalline defects in both graphene layers4,5 and maximal area of Bernal stacking, which is necessary for bandgap tunability6. Here we demonstrate that in an oxygen-activated chemical vapour deposition (CVD) process, half-millimetre size, Bernal-stacked BLG single crystals can be synthesized on Cu. Besides the traditional ‘surface-limited’ growth mechanism for SLG (1st layer), we discovered new microscopic steps governing the growth of the 2nd graphene layer below the 1st layer as the diffusion of carbon atoms through the Cu bulk after complete dehydrogenation of hydrocarbon molecules on the Cu surface, which does not occur in the absence of oxygen. Moreover, we found that the efficient diffusion of the carbon atoms present at the interface between Cu and the 1st graphene layer further facilitates growth of large domains of the 2nd layer. The CVD BLG has superior electrical quality, with a device on/off ratio greater than 104, and a tunable bandgap up to ∼100 meV at a displacement field of 0.9 V nm−1.