Jong Hyun Ahn

Bio: Jong Hyun Ahn is an academic researcher from Yonsei University. The author has contributed to research in topics: Graphene & Graphene nanoribbons. The author has an hindex of 74, co-authored 287 publications receiving 39786 citations. Previous affiliations of Jong Hyun Ahn include National University of Singapore & University of Illinois at Urbana–Champaign.

Biomimetic Tactile Sensors Based on Nanomaterials.

Abstract: Tactile sensor technology has been researched extensively in response to the increasing demand for robotic and wearable healthcare systems. Studies on tactile sensory systems have primarily focused on achieving two goals: (1) developing technologies with high sensing abilities that mimic the biological functions and characteristics of the sensory systems of human skin and (2) satisfying the requirements of wearable device applications by fabricating mechanically flexible devices with low-power data analysis and processing abilities. In this Perspective, we present recent advances in artificial tactile sensory systems, which are based on biomimetic technologies that exhibit functional features of biological systems including mechanoreceptors and human skin sensory neurons for human-machine interfaces. We also discuss the opportunities, current challenges, potential solutions, and future investigative directions pertaining to this field.

Synthesis and applications of graphene electrodes

Abstract: The near explosion of attention given to graphene has attracted many to its research field. As new studies and findings about graphene synthesis, properties, electronic quality control, and pos sible applications simultaneous burgeon in the scientific community, it is quite hard to grasp the breadth of graphene history. At this stage, graphene’s many fascinating qualities have been amply reported and its potential for various electronic applications are increasing, pulling in ever more newcomers to the field of graphene. Thus it has become important as a community to have an equal understanding of how this material was discovered, why it is stirring up the scientific com munity and what sort of progress has been made and for what purposes. Since the first discovery, the hype has expediently led to near accomplishment of industrial-sized production of graphene. This review covers the progress and development of synthesis and transfer techniques with an emphasis on the most recent technique of chemical vapor deposition, and explores the potential applications of graphene that are made possible with the improved synthesis and transfer.

Graphene-Based Heat Spreader for Flexible Electronic Devices

Abstract: Graphene known for its superb physical properties, such as high transparency and thermal conductivity, is proposed as a solution to the problem of thermal management of the electronic devices, requiring transparency and cooling. It is shown that graphene heat spreader layer drives the heat out of the device more efficiently as compared with the commercially used metal thin films for integrated circuit cooling. An application of graphene heat spreader is proposed and tested in chip-on-film packaging. Graphene performance is compared with a gold layer with a similar transparency experimentally and theoretically as a proof of the efficient thermal management capability of graphene.

2D Materials for Skin-Mountable Electronic Devices.

Abstract: Skin-mountable devices that can directly measure various biosignals and external stimuli and communicate the information to the users have been actively studied owing to increasing demand for wearable electronics and newer healthcare systems. Research on skin-mountable devices is mainly focused on those materials and mechanical design aspects that satisfy the device fabrication requirements on unusual substrates like skin and also for achieving good sensing capabilities and stable device operation in high-strain conditions. 2D materials that are atomically thin and possess unique electrical and optical properties offer several important features that can address the challenging needs in wearable, skin-mountable electronic devices. Herein, recent research progress on skin-mountable devices based on 2D materials that exhibit a variety of device functions including information input and output and in vitro and in vivo healthcare and diagnosis is reviewed. The challenges, potential solutions, and perspectives on trends for future work are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.