Researchers and manufacturers of flexible and printed materials have envisioned a future where flexible electronics have multiple applications. The first expected commercial applications coming into the market include smartphones, tablets, TV screens, wearables, and bio-sensors.

However, the electronics supply chain can also expect to see organic transistors and organic semiconductors in the mix in a relatively short period of time, according to Takao Enomoto, director of Chemical Materials Development at Tanaka Kikinzoko Kogyo Japan. Enomoto collaborated in the Nanoparticle Chemisorption Printing Technique for Conductive Silver, a research paper published by Nature Research.

The future is flexible

New materials and new technologies are required for the manufacture of flexible printed electronics. This includes the use of silver metals. One of the characteristics of silver is that it oxidizes easily. This makes silver very easy to form at low temperatures. The product that results from this is a very thin, embeddable, transparent, and conductive film, like the one shown below.

Transparent flexible substrates with 0.8 μm wiring. Photo courtesy: AIST, the University of Tokyo, Yamagata University, Tanaka Kikinzoku Kogyo K.K., and the Japan Science and Technology Agency (JST)

The transparent conductive film is the result of the collaboration between Tanaka Kikinzoku Kogyo with Yamagata University, the Flexible Electronics Research Center of the National Institute of Advanced Industrial Science and Technology (AIST), the University of Tokyo, and the Japan Science and Technology Agency (JST).

All the applications will include flexible touch panel sensors using Surface Photo-Reactive Nanometal Printing (SuPR-NaP) printing. Tanaka has developed a method of synthesizing silver nanoparticles in large quantities through pyrolysis of silver amine complexes. All the silver particles are encapsulated in alkylamine and have the property of sintering at low temperatures. This ink can be used to achieve conductivity at low temperatures.

Technology enables flexibility for manufacturing

The SuPR-NaP technique is used to create silver nanoparticles that can be used for circuit printing at low temperatures on flexible film and other media.

SuPR-NaP printing process. Source: AIST, the University of Tokyo, Yamagata University, Tanaka Kikinzoku Kogyo K.K., and the Japan Science and Technology Agency (JST).

 Flexible printed electronics applications

Applications of this film include the manufacture of flexible printed electronics, flexible screens, flexible devices, wearables, ubiquitous healthcare monitoring, sensors, bridges and freeways. 

The relatively new industry of wearable devices demands include the application of flexible substrates such as printing electronic circuits on substrates used in applications such as touch panel sensors. Electronics manufacturers including Samsung, LG, and Lenovo have been working on commercial flexible displays concepts for the last few years and have produced the first prototypes. 

We have been seeing flexible displays and device prototypes at industry shows for a few years now. It’s only a matter of time until fully functional flexible printed electronics become part of our daily life. While the totality of the electronics supply chain gets ready for the demanding days ahead, here is a look at how we can expect our days to be in the flexible future: