Ultra Thin Circuits

Ultra thin film-like organic transistor integrated circuits are being developed by a research group led by Professor Takao Someya and Associate Professor Tsuyoshi Sekitani of the University of Tokyo, who run an Exploratory Research for Advanced Technology program sponsored by the Japan Science and Technology Agency, in collaboration with Siegfried Bauer's group at the Johannes Kepler University Linz, Austria.

The circuits are extremely lightweight, flexible, durable and thin, and conform to any surface. They are just 2 microns thick, just 1/5 that of kitchen wrap, and weighing only 3g/m^2, are 30 times lighter than office paper. They also feature a bend radius of 5 microns, meaning they can be scrunched up into a ball, without breaking. Due to these properties the researchers have dubbed them "imperceptible electronics", which can be placed on any surface and even worn without restricting the users movement.

The integrated circuits are manufactured on rolls of one micron thick plastic film, making them easily scalable and cheap to produce. And if the circuit is placed on a rubber surface it becomes stretchable, able to withstand up to 233% tensile strain, while retaining full functionality.

"This is a very convenient way of making electronics stretchable because you can fabricate high performance devices in a flat state and then just transfer them over to a stretchable substrate and create something that is very compliant and stretchable just by a simple pick and place process."

In the future, the group would like to expand the capabilities of these circuits and open a wide range of new applications, from health monitoring systems, wearable medical instruments, and even robotic skins.