Online ceremony held to celebrate dawn of the year of the White Ox
Ajou University decided to organize its annual ceremony marking the start of the new year online, still determined to share New Year’s greetings and the University’s major accomplishments of the past year and plans for the new year with students notwithstanding the pandemic. The online ceremony featured a New Year’s address from University President Park Hyung-ju; the announcement of Ajou Vision 4.0, a mid- to long-term plan for the University’s development; and discussions of the University’s performance in 2020 and major plans for 2021. The ceremony also shared the top 10 headlines featuring Ajou University from 2020, showing notable achievements and progress that shone light on the school in the midst of COVID-19. Ajou President Park said during his address: “I am grateful for the dedication, hard work, and understanding that members of the Ajou community have shown us this past year.” He added: “Let us embark on this new year with new hopes, new expectations, and new attitudes.” “As a university committed to actively leading innovation in education,” Park explained, “Ajou will continue to develop a new paradigm in education with substantial effects on more disciplines and programs.” He went on: “We will continue with our various initiatives for strengthening the University’s research capabilities as well.” Ajou Vision 4.0, released upon the University’s anniversary in 2019, lays down the University’s goals for intermediate- and long-term growth, defining the trajectories in which education, research, and culture on campus are to evolve. # Watch the University President’s New Year’s address #Watch Ajou Vision 4.0 / Reflection on 2020 / Main Plans for 2021 # Watch Top 10 Headlines from Ajou 2020
Prof. Shim Tae-soup’s team develops stimuli-responsive hydrogels
Prof. Shim Tae-soup (left) and Kim Min-a (right) A team of Ajou researchers led by Prof. Shim Tae-soup (Dept. of Chemical Engineering and Dept. of Energy Systems Research) has developed stimulus-responsive hydrogel structures whose surfaces can be controlled at the micrometer level. The team’s work on generating crease patterns using stimulus-responsive hydrogels was entitled, “Stepwise Evolution of Crease Patterns on Stimuli-Responsive Hydrogels for the Production of Long-Range Ordered Structures,” and published as the featured article in the December issue of Advanced Materials Interfaces, an international journal on cutting-edge materials. Kim Min-a, a master’s candidate in the Department of Energy Systems Research, also participated as the first author. Crease-prone soft matter can change form easily when thermal energy is applied. Much applied research has been conducted to utilize its pliable physico-chemical properties and microstructures through application of a variety of external stimuli. Surface creases found on organisms, including fingerprints and palm prints, have especially garnered attention for their potential to increase the surface areas of industrial materials and for their superior fluid and elastic properties. Attempts have been made to simulate these creases in engineering. The mechanisms for forming such creases, however, occur arbitrarily without seeming patterns, frustrating researchers’ repeated attempts to create uniform and ordered two-dimensional crease structures. Prof. Shim’s team successfully created micro-level anisotropic creases on the surfaces of hydrogel films utilizing the reaction-diffusion system and the viscoelasticity of soft matter. As a result, the hydrogel films expanded in response to pH variations, with surface creases forming hexagonal or rectangular structures step by step. Furthermore, the team found that yeast cells cultured on these crease structures were aligned with reversibility, empirically demonstrating that the crease patterns are capable of aligning themselves through the mechanism of surface topology without undergoing chemical reactions with biomaterials. Prof. Shim explained: “The new crease formation mechanism we have discovered, by controlling the structures of polymer films step by step using their anisotropic creases, can be applied to a wide range of materials and stimuli. It can also be used to help develop platforms for inducing the growth of various biomaterials and analyzing cells.” The study was made possible with support from the National Research Foundation of Korea’s basic research program.
Prof. Yoo Young-dong discovers new mixed-dimensional heterostructures
Prof. Yoo Young-dong’s team has developed new mixed-dimensional in-plane heterostructures, generating hopes for the invention of a new core material for flexible and transparent electric and energy semiconductors. The team, led by Prof. Yoo (Dept. of Chemistry, pictured) has found a new method for synthesizing mixed-dimensional in-plane heterostructures, and published their findings under the title, “Mixed-Dimensional In-Plane Heterostructures from 1D Mo6Te6 and 2D MoTe2 Synthesized by Te-Flux-Controlled Chemical Vapor Deposition” in Small, an international nanoscience journal. Kim Hyeon-kyeong, currently in the combined postgraduate program at Ajou University, is listed as the first author on this paper that went on to be featured on the journal’s November 26 issue. Chalcogen compounds, used in two-dimensional semiconductors, promise utility as materials for next-generation electric and energy semiconductors for wearable devices and rollable displays as the rollable and transparent compounds possess superior electric and optic properties. However, the significant contact resistance that arises when these compounds and metallic electrodes are combined to create two-dimensional semiconductors has consistently limited compound performance. Prof. Yoo’s team used the chemical vapor deposition method (i.e., depositing films on semiconductors and metals through the vaporization of precursors with heat or plasma) to control the dimensions of the synthetic materials to be created, as the method using is suited to controlling the flux of precursors. As a result, the researchers were able to synthesize mixed-dimensional metal-semiconductor heterostructures. The metallic molybdenum telluride (Mo6Te6) on the first dimension is combined horizontally with the semiconductor-like molybdenum ditelluride (MoTe2) on the second dimension to create these novel structures. The team’s discovery provides new clues to the solution for minimizing contact resistance. A precursor refers to a material that transforms into a desired substance through chemical reactions. The team, moreover, has demonstrated the specific mechanism for synthesizing low-dimensional substances through flux control. When the amount of tellurium (Te) supplied per unit of time remains small, one-dimensional Mo6Te6 is synthesized with molybdenum (Mo) and Te atoms matched in an equal ratio. When the amount of Te supply per unit of time increases, two-dimensional MoTe2 is obtained, with double the amount of Te atoms bonding with Mo atoms. This mechanism can help synthesize not only mixed-dimensional materials, but also either one-dimensional or two-dimensional materials. The diverse low-dimensional materials so synthesized can be applied to electronics, optoelectronics, and catalysts. Prof. Yoo remarked: “The synthesis mechanism we have discovered is simple and expandable, and is therefore expected to help create much more diverse mixed-dimensional heterostructures. I expect these new synthetic structures to become core materials for making flexible and transparent next-generation electronic and energy semiconductors.” The study has been conducted with support from the Ministry of Science and ICT and the National Research Foundation of Korea’s New Researcher Support Programs.