A*STAR’s ultrahigh barrier film technology will significantly increase the life span of flexible electronic devices such as inorganic electroluminescent displays (pictured), expanding the practical applications of plastic electronics.
Flexible electronics promise to form the basis for the next generation of electronic devices, and have already been applied in a range of prototypes and limited applications. This technology has made electronic paper, ultrathin flexible displays and low-cost solar cells a reality, but the resilience of these devices to practical environments, particularly moisture, has been an obstacle to commercial mass-production.
Now, with a major investment by US-based Applied Materials, Tera-Barrier Films—a recent spin-off from A*STAR—is even closer to commercializing a revolutionary protective film for plastic electronics that meets all of the moisture-barrier requirements for future applications.
Existing commercial protective films for plastic electronics provide a barrier to oxygen and water molecules, but due to unavoidable defects in the thin, flexible oxide films, these barriers still allow the diffusion of about 1/1,000th of a gram of water vapor per square meter each day at 90% relative humidity and 25 °C. Although low, this level of water penetration is 1,000 times higher than the level required for practical applications, and is sufficient to significantly shorten the lifetime of the organic materials at the heart of these devices. To minimize molecular diffusion, the protective films are constructed by stacking alternating layers of ultrathin inorganic (oxide) and organic films. This approach lengthens the diffusion path for invading molecules, but does not block the path completely.
Researchers at A*STAR’s Institute of Materials Research and Engineering (IMRE), led by Senthil Ramadas who is now chief technology officer of Tera-Barrier Films, took a different and innovative approach. Instead of stacking multiple layers to increase the film’s resistance to water molecule penetration, the researchers ‘plugged’ the defects in the barrier oxide layer with nanoparticles.
Not only did they succeed in increasing the barrier property by more than 1,000 times, surpassing application requirements, they also reduced the number of layers required to just two—a considerable improvement in manufacturing and material efficiency. The new nano-engineered film has a barrier property of better than 10–6 g/m2/day of water vapor at 90% relative humidity and 39 °C. The barrier stack consists of oxide layers and nanoparticulate layers that both seal the defects in the film and react with moisture and oxygen.
Conventional protective films (top) slow the diffusion of oxygen and water molecules by lengthening the diffusion path. In the IMRE’s new ultrahigh barrier film, defects in the film are plugged with nanoparticles to more effectively block molecular diffusion.
Such are the prospects for this technology that Applied Materials, a global leader in nano-manufacturing technology, has made a major strategic investment in Tera-Barrier Films through its venture capital arm Applied Ventures. “We are pleased that our investment in Tera-Barrier will be used to support the commercialization of this breakthrough technology to enable a new generation of advanced devices,” said J. Christopher Moran, vice president of Applied Ventures, in a media release on August 25.
The performance of the ultrahigh barrier film technology has been validated by solar cell and flexible display manufacturers. “Tera-Barrier Films is in the process of securing product qualification and sample orders and has strong subcontract partnerships in place for scalable production of high performance barrier films,” says Mark Auch, who has been working on commercialization of this technology and who now acts as chief executive officer of Tera-Barrier Films.
“The company maintains a growing portfolio of 29 patents in transparent gas barrier technology, encapsulation and gas permeation measurement systems, and works closely with flexible solar cell, printed electronics and display manufacturers to develop total barrier solutions for these applications,” says Ramadas, “the technology, know-how and patent portfolio generated from IMRE/A*STAR will provide Tera-Barrier Films with a competitive edge and enable us to offer a total barrier solution to customers.”
About Tera‐Barrier Films
Tera-Barrier Films Pte. Ltd was jointly founded by Senthil Ramadas and Mark Auch with the support of Exploit Technologies, the strategic marketing and commercialization arm of A*STAR. Tera-Barrier Films is a spin-off company from A*STAR’s Institute of Materials Research and Engineering.
About Applied Ventures
Applied Ventures LLC, a subsidiary of Applied Materials Inc., invests in early stage technology companies with high growth potential that provide a window on technologies that advance or complement Applied Materials’ core expertise in nanomanufacturing technology.
About the Institute of Materials Research and Engineering
The Institute of Materials Research and Engineering (IMRE) was established in 1997 with the aim of becoming a leading research institute for materials science and engineering. The IMRE has developed strong capabilities in materials analysis, characterization, materials growth, patterning, fabrication, synthesis and integration, and has established reseach and development program in collaboration with industry partners.
