Applications of Diamond-like Carbon (DLC) in a variety of fields

The keyword in the Tetsuya Suzuki Laboratory of the Department of Mechanical Engineering at Keio University is ''nanomaterials''. The researchers in the Suzuki Lab are working to develop high-performance thin-film materials and to analyze such materials at the atomic level. In particular, Diamond-like Carbon, or DLC for short, is the main target. The researchers improve the DLC films and apply them in a variety of fields.

DLC is an amorphous carbon film with the same quality as diamond. It is superior in terms of hardness, smoothness, gas barrier performance and biocompatibility. It's already applied to some fields such as PET bottles and automotive components.

"We synthesize films from gases and apply them in a variety of fields. It's only been about 30 years since researchers were able to synthesize DLC from gases. It's synthesized by decomposing hydrocarbon gases and stacking individual atoms. And DLC is similar in structure to diamond. Diamond we know as a gemstone has mechanical properties that make it useful as more than just a gemstone. It's extremely hard, the best conductor of heat. Moreover, it doesn't let gases pass through because it is high-density. DLC also has those properties. Our research is the application of the DLC films which has those properties in a variety of fields."

One issue in many applications of DLC is reducing the cost of synthesizing DLC films. To synthesize DLC films quickly and at low cost, the Suzuki Lab is working to synthesize them at atmospheric pressure without vacuum equipment previously needed. However, it's been pointed out that the DLC films synthesized at atmospheric pressure have lower performance than those synthesized under vacuum conditions. So, the researchers are improving the performance of DLC films synthesized at atmospheric pressure.

"We place a great emphasis on international competitiveness. I think one problem of researches in universities is that researchers make good things regardless of high cost. Even when a researcher comes out with a new product, it won't be widely accepted if it costs ten times as much as an old one to perform twice as well. It is not until we develop a higher-performance product than an old one at about the same low price that it will attract many companies from different industries and it can be applied in a variety of fields."

The stent, which is a medical instrument, is one of the applications of DLC films. The Suzuki Lab is currently developing DLC-coated stents as commercial products. Stents play a role in dilating narrow blood vessels. It's been confirmed that DLC-coated stents are smoother, which inhibits clotting.

In addition, the Suzuki Lab develops low-cost solar cells using DLC films, cutting tools coated with hard films and sliding components coated with diamond films.

"For example, DLC films have been applied in the automotive window which is accounts for a large part in the heavy. Automakers have used plastic for the windshield and rear window which inevitably get scratched for a long time. And coating the windows with DLC films can prevent them getting scratched, by either fingernails or grit. One way to coat a large area cheaply with the DLC is a thin-film-forming technology using atmospheric-pressure plasma. To sum up, as I often mention in research papers, improving three characteristics of DLC - hardness, gas barrier performance and antithrombogenicity - lead to contribute to society in the various fields, I think."





Related Articles

At Keio University, the Sugiura Laboratory, in the Department of Mechanical Engineering (Faculty of Science and Technology) is investigating various phenomena through analysis and experiment. These phenomena involve coupling between electromagnetics and mechanical dynamics, as well as nonlinear dynamics. Currently, the researchers are focusing on three topics. The first is nonlinear oscillations in superconductive magnetic suspension systems. In such systems, objects are levitated, so energy loss due to friction is very low.


This is an interactive optic fiber cloth. It is made of side-emitting diffusive optic fibers so computer controlled light patterns can be displayed on it, and by attaching light receivers as well as light emitters, optical signals can be input using infrared light.

"Originally, we came across the light-emitting fabric, where light is emitted from the optical fiber surface. Conversely, we thought it could be used to input data by receiving light through the surface. So, we've created this kind of interface."

At Keio University, the Takahashi Laboratory, in the Department of System Design Engineering (Faculty of Science and Technology) is doing research to develop products and systems that are useful to society, through an approach called model-based control.

At the Morita Lab in the Department of Mechanical Engineering of the Keio University Faculty of Science, researchers are advancing with research and development of unique robots from the perspective of mechanisms, control, skill, and an integration of each of these areas.

The Hagiwara Lab in the Department of Information and Computer Science of Keio University's Faculty of Science and Technology is trying to realize a robotic brain that can carry on a conversation, or in other words, a robotic brain that can understand images and words and can carry on thoughtful communication with humans.

The Matsutani Lab in the Department of Information and Computer Science of Keio University's Faculty of Science and Technology is researching interconnection networks on a variety of scales ranging from large-scale data-center networks for Big Data to micro-networks such as Network-on-Chips.

At Keio University, the Ishigami Laboratory, in the Faculty of Science and Technology, Department of Mechanical Engineering, is investigating robotic mobility systems. The main mission of this group is to perform fundamental and applied research for application to extreme environments, notably lunar and planetary rovers.

"In our lab, we focus on field robotics that works for extreme environments."

In the Department of Applied Chemistry at Keio University's Faculty of Science and Technology, the Katayama Laboratory is doing research in the field of electrochemistry.

One aspect of the Lab's research is investigating electrochemical reactions in electrolytes called ionic liquids, and applying them to technologies, including new batteries and electroplating.

At Keio University, the Mitsukura Laboratory, in the Department of System Design Engineering, researches how to extract required information from biometric , image, audio signal data. To achieve this, the researchers utilize technologies such as signal processing, machine learning, pattern recognition, artificial intelligence, and statistical processing.

At the Terakawa Laboratory of Keio University's Department of Electronics and Electrical Engineering, research is being conducted on technology that explores and utilizes laser-material interaction to contribute to engineering, biotechnology, and medicine.

Here, keywords of the research are laser processing, micro- and nano-structure, and biomedical applications.

In particular, the laboratory is focused on processing with a femtosecond laser that enables them to achieve more precise processing than with lasers currently used broadly in industry.

Reno J. Tibke - December 21, 2013

JTFF - Japanese Technology from the Future Friday! -

This week it's a new force-reactive, wireless, two way touching that's so fast it seems instantaneous, and Kirobo, the cute little space robot that only speaks Japanese, finally came out of ISS storage to talk with astronaut Koichi Wakata.

• • •

From astronomical telescopes to household-use cameras, from aircraft to cellphones, from semiconductor devices to medical instruments... All kinds of optical, mechanical, and electronic products are manufactured using high-precision manufacturing technologies.

The precision of manufacturing technology has advanced from the micrometer to sub-micrometer level, and recently, to the nanometer scale. In the near future, manufacturing techniques are expected to reach the precision level of operating individual atoms.

At Keio University, the Ogawa Laboratory, in the Department of Mechanical Engineering, Faculty of Science and Technology, is working to establish technology for measurement inside fuel cells. The aim is to enable stable electric current generation in fuel cells, which have recently undergone rapid advances in development.

At Keio University, the Toyama Laboratory, in the Department of Information and Computer Science (Faculty of Science and Technology), researches how to operate database technology to support IT simply and efficiently. The Toyama Lab takes a threefold approach to this research, aiming to construct and implement new systems from the three viewpoints of extension, combination, and application.

The Ikaga Research Laboratory of Keio University’s System Design Engineering Department conducts research on the core issue of sustainability in terms of both architecture and urban planning. The group examines how this informs both the design of domestic environments to actively promote health, and urban environments conducive to a low-carbon approach. Currently the lab is focusing on three main themes: health, intellectual productivity, and low-carbon.