Occurring in everything from radio astronomy to medicine, terahertz radiation — electromagnetic waves whose frequencies range from 100 gigahertz to 10 terahertz — has a wide range of uses. Research has intensified on it recently, driven by the demand for higher bandwidth in wireless communications and for depiction in security applications.
Researchers at Chalmers University of Technology, located in Gothenburg, Sweden, have used graphene transistors on plastic substrates to develop a flexible detector for terahertz frequencies. As the first mechanically flexible device of its kind, it can extend the use of terahertz technology to flexible-electronics applications such as wireless sensor networks and wearable technology.
The incorporation of graphene is key: Its unique electronic features and flexible nature make it a promising material for integration into plastic and fabric, enabling new applications for the internet of things (IoT). Graphene is ultra-thin, with the ability to withstand high strain; it also conducts electric current extremely well. The Chalmers team’s research, published in the scientific journal Applied Physics Letters, represents an answer to the longstanding challenge of enabling flexible, portable and less expensive solutions for graphene’s many potential applications.
The researchers credit advancements in polymer technology for the promotion of flexible electronics and the fabrication of high-frequency devices on flexible substrates.
At room temperature, the new detector can detect signals in the frequency range 330 to 500 gigahertz. It can be applied to terahertz-camera imaging as well as sensor identification of various substances. It may be beneficial to health care, where terahertz waves can detect skin cancer. Additional potential applications include imagining sensing for vehicles, where the device can be utilized for night vision or seeing through rain, snow and fog; leakage detection; next-generation wireless communication; and many more aspects of what the researchers refer to as the "flexible future."
The translucent device drew attention at the EU Tallinn Digital Summit, which focused on the role graphene can play in digital innovation and Europe’s digital future. The summit displayed a number of technological innovations made possible by graphene and related materials.