Electronics

ETH Zurich researchers create ultra-thin, flexible circuit

ETH Zurich researchers create ...
Researchers at ETH Zurich have created ultra thin, clear and flexible circuitry
Researchers at ETH Zurich have created ultra thin, clear and flexible circuitry
View 4 Images
Researchers at ETH Zurich have created ultra thin, clear and flexible circuitry
1/4
Researchers at ETH Zurich have created ultra thin, clear and flexible circuitry
The circuitry is layered on a substance called parylene
2/4
The circuitry is layered on a substance called parylene
The circuitry is so thin it can sit on top of a contact lens, or be wrapped around a human hair
3/4
The circuitry is so thin it can sit on top of a contact lens, or be wrapped around a human hair
The technology could be used as a smart textile for sports, or to monitor physiological factors like body temperature
4/4
The technology could be used as a smart textile for sports, or to monitor physiological factors like body temperature
View gallery - 4 images

Researchers at the Swiss Federal Institute of Technology in Zurich (ETH Zurich) have created clear, flexible electronic circuitry that is so thin it can sit upon the surface of a contact lens, or be wrapped around a human hair. The research, led by Dr. Giovanni Salvatore, could ultimately be used for implantable medical devices. One such potential application suggested by the team is a “smart contact lens” that could monitor intraocular pressure for glaucoma patients.

In order to create the circuits, the layers are deposited using e-beam evaporation, atomic layer deposition, spin coating and radio frequency sputtering. The structuring is created using ultraviolet (UV) lithography and etching. The circuits are created on a substance called parylene, an insulator that is traditionally used as a protective coating for electronic devices and components.

“Parylene is a suitable material because it is able to withstand quite high temperatures (150 degrees Celsius [302ºF] in our process) and it is also not attacked by the etchands and solvents used during the fabrication process,” explains Niko Münzenrieder, one of the authors of the research. “Furthermore, it is transparent and bio-compatible, which is beneficial for different applications like the smart contact lens. Of course, it is also flexible.”

The circuitry is so thin it can sit on top of a contact lens, or be wrapped around a human hair
The circuitry is so thin it can sit on top of a contact lens, or be wrapped around a human hair

The research team envisages using a wireless power source for the contact lens, such as a magnetic field. Harvesting solar or kinetic energy on the parylene surface are also potential approaches that the team have considered. Besides the smart contact lens, Münzenrieder suggests that the technology could be used as a smart textile for sports or in a hospital to monitor physiological factors like body temperature.

Münzenrieder says that the team does not expect the technology to be commercially available in less than five years, but the future of its research will be no less compelling.

“The energy supply of the flexible circuits is definitely a hot topic,” he explains. “At the same time we are also working on more complex circuits, and sensors to monitor, e.g. humidity or different gases. Besides this we are also exploring the possibility of integrating the membrane with other objects like textiles and elastic materials to realize something like a smart skin for robots or prostheses.”

The research has been published in the journal Nature Communications.

Source: ETH Zurich

View gallery - 4 images
2 comments
Rocky Stefano
From the source article they mention the substrate is 1 micron thick but don't mention what the overall circuit thickness is when finished. I've worked with various companies in the past to produce circuits at a maximum thickness of 15-20 microns so considering we did that over 8 years ago this isn't as exciting as I'd hoped.
Rafael Kireyev
I think, it would be great if they based on this diminutiveness would try to create a system of continuous monitoring of the oral cavity. For example, maybe, they can use the released places of the wisdom teeth.