Department+of+Mechanical+Engineering
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Micropatch Made of DNA
Researchers reported the fabrication of microstructure arrays of DNA materials using topographic control. This method provides a platform for forming multiscale hierarchical orientations of soft and biomaterials using a process of simple shearing and controlled evaporation on a patterned substrate. This approach enables the potential of patterning applications using DNA or other anisotropic biomaterials.
DNA is one of the most abundant biomaterials found in all living organisms in nature. It has unique characteristics of fine feature size and liquid crystalline phase, enabling to create various kinds of microstructure DNA arrays. Based on these characteristics, DNA has been used as a building block for “origami” and textile art at the nanometer scale.
A KAIST research team led by Professors Dong Ki Yoon and Hyungsoo Kim fabricated a DNA-based micropatch using the “coffee ring effect” and its multi-angle control technology, which was published online in Nature Communications on June 7.
The research team used cheap DNA material extracted from salmon to realize the micropatch structure with well-aligned knit or ice cream cone shapes. When the DNA material in an aqueous solution is rubbed between two solid substrates while water is evaporating, DNA chains are unidirectionally aligned to make a thin film such as in LCD display devices. The DNA chains can make more complex microstructures such as knit or a texture with ice cream cone shapes when the same procedure is carried out in topographical patterns like microposts (Figure 1). This can be applied to make metamaterials by mixing with functionalized gold nanorods to show plasmonic color.
Plasmon resonance is a phenomenon in which electrons vibrate uniformly on the surface of a substrate made of metal, reacting only to light that matches a specific energy to enhance the clarity and expression of colors. For this, the most important factor is the orientation in which the gold nanorods align. That is, when the rods are aligned side by side in one direction, the optical and electrical characteristics are maximized. The research team focused on this point and made the DNA micropatch as a frame to orient the gold nanorods in a unique shape and fabricated a plasmonic color film (Figure 2).
Professor Yoon said this study is meaningful in that it deals with the evaporation phenomenon, which has not been studied much in the field of polymers and biopolymers in terms of basic science. He explained, “This will also help maximize the efficiency of polymeric materials that can be orientated in coating, 2D, and 3D printing applications. Furthermore, DNA that exists infinitely in nature can be expected to have industrial application value as a new material since it can easily form complexes with other materials as described in this study.”
(Figure 1. The DNA micropatch using topographic control. (a) The experimental scheme.
(b) Enlarged image of (e). (c-e) Different micropatches made of DNA using different shearing directions.)
(Figure 2. The knit-like structures made of DNA-gold nanorod complex. (a,b) Optical
and polarized optical microscopy images. (c-f) Plasmonic colors reflected from aligned DNA-gold nanorod complex depending on the sample rotation.)
2019.07.01 View 32630 -
Humanoid Robot Research Center Opened
(Photo from left: Kyong-Hoon Kim from Korea Evaluation Institute of Industrial Technology, Vice President of Research at KAIST Hee-Yoon Lee, Director Oh, Jong-Hwan Kim at the Ministry of Trade, Industry and Energy, President Ki-Han Park at the Korea Institute for Robot Industry Advancement, and Dean of KAIST Institute Yun Chol Chung.)
KAIST opened its Humanoid Robot Research Center on January 19 at the KAIST Institute. Endorsed by the Ministry of Trade, Industry and Energy with 15 billion KRW funding over five years, the center will conduct research for advancing humanoid robot technology and fostering research fellows in the field.
Professor Jun Ho Oh at the Department of Mechanical Engineering will serve as the director of the center. Team KAIST under Professor Oh won the 2015 DARPA Robotics Challenge (DRC) with its humanoid robot DRC-HUBO, beating 23 teams from six countries.
Professor Oh said, “I believe we have already achieved technological prowess through developing the HUBO robot over the past decade. The center will continue to strive for further development of original technology crucial for humanoid robots’ key components. We want to pave the way for having enough of our own technology and needing to bring in technology from abroad. Professor Oh said he will focus on fields such as high-efficiency, high-powered electric drives and hydraulic system humanoid robot capable of executing solid manipulability with high confidence and object recognition intelligence technology. In addition, he said the center will develop module type and extended open software in an effort to disseminate robot technology.
2017.01.23 View 6968 -
Two Undergraduate KAIST Students Publish a Book on Health Management
Joonho Suh of the Aerospace Engineering Department and Jiho Suh of the Mechanical Engineering Department are both brothers and undergraduates at KAIST.
The Suh brothers, who are three years apart, have recently published a self-help book in English on staying healthy entitled “A Scientific Approach to Building Muscle: Mass Effect.”
The book introduces techniques to build muscles, adapting them from an engineering concept called "Active Torque Control (ACT)," the management of turning forces imposed on a vehicle. Just as ACT influences the performance of a vehicle, good exercise involves the right degree of body angles and the right direction of body movements to keep the best posture necessary for burning calories and strengthening muscles.
In the book, they also suggest healthy diet plans based on scientific knowledge and data that the writers borrowed from such fields as anatomy, physiology, and motor mechanics to maintain a healthy weight.
Joonho Suh said,
“If we understand the mechanism of how our body works, the chances are high we will have good muscle tone and a balanced diet. We used a great deal of scientific knowledge and turned it into a health management program that can be customized per individual needs.”
The younger brother, Jiho, added,
“In fact, we applied our methods in the book to beginners who took weight training and fitness for one hour a day for one month, we learned that their muscle mass increased by 1-1.5 kg while losing body fat by 2-3 kg.”
The brothers said they planned to publish a Korean language version of the book next year.
The authors of "Mass Effect": Joonho Suh (left) and Jiho Suh (right)
2015.10.26 View 6623