Researchers found a way to implement a composite material in the form of nanomembrane for skin electronics.
Skin electronics can be employed in a wide range of applications such as health monitoring, health diagnosis, virtual reality, and human-machine interface. These devices are thin, flexible electronic circuits that can be mounted on the skin for monitoring data.
To implement the, soft and stretchable components are required that are compatible with human skin. For reliable operation and high-quality performance, a stretchable conductor which features ultrathin thickness, metal-like conductivity, high stretchability, and ease of patternability is required. However, having all these properties simultaneously is difficult, as they often have trade-offs between one another.
Led by professor Hyeon Taeghwan and Kim Dae-Hyeong, researchers at the Center for Nanoparticle Research within the Institute for Basic Science (IBS) in Seoul, South Korea figured a new method to fabricate a composite material in the form of nanomembrane, which comes with all of the above-mentioned properties. The new material consists of metal nanowires that are tightly packed in a monolayer within ultrathin rubber film.
The new material was made using the “float assembly method,” that takes advantage of the Marangoni effect, which occurs in two liquid phases with different surface tensions. When there is a gradient in surface tension, a Marangoni flow is generated away from the region with lower surface tension towards the region with higher surface tension. This results in dropping liquid to spread thinly across the surface of the water.
The nanomembrane is created using a float assembly method which consists of a three-step process. The structure allows efficient strain distribution in ultrathin rubber film, leading to over 1,000%, and a thickness of only 250 nm. According to the researchers, the nanomembrane can be patterned using photolithography, which is a key technology that is widely used for manufacturing commercial semiconductor devices and advanced electronics. Therefore, it is expected that the nanomembrane can serve as a new platform material for skin electronics.
The research has been published in the journal Science.