A team from the University of Cambridge has developed an inkjet-printed transistor, which is sensitive enough to accurately detect electrophysiological signals from the skin when used in conjunction with a wearable device.
In the virtual environment, for example, the tracking of subtle eye movements by electro-oculography is needed for a better, more realistic depiction which relies on elements such as depth of field rendering. Compared to other thin film technologies such as silicon or metal oxides, the transistor’s power consumption is one thousand times less and the signal-to-noise ratio one hundred times better.
The results demonstrate the potential of using low-cost inkjet-printing technology to directly integrate biomaterials with electronics, in order to create new applications at the forefront of the electronics-biology interface, such as the tracking of eye movements in virtual and augmented reality.
“This is the first time such a high performance printed transistor has been achieved that demonstrates good reliability over several months, without changing characteristics,” said Dr Chen Jiang, the paper’s first author. “This transistor improves upon typical organic transistors that have a lower level of reliability of just a few days or even a few hours.”
Dr David Hasko, the paper’s co-author from the Department of Engineering, said: “This application demonstrates a further example of how it is possible to fabricate a whole circuit using just a single, highly affordable, inkjet printing tool that puts a fabrication plant within reach of most university departments. It would be an excellent way of introducing, for example, design rules and micro-fabrication in a practical way.”