Stretchable circuitry inspired by rose petals

Chuck Bednar for redOrbit.com – @BednarChuck

Drawing inspiration from the properties of rose petals, a team of researchers from the Hong Kong Polytechnic University are developing a new type of stretchable electronic devices that could effectively keep circuitry from cracking under extreme duress.

As Gizmodo explained on Friday, the concept of flexible electronics is growing exponentially in terms of appeal due to how handy and downright cool it would be to have a tablet that could be rolled up or a phone that could bend. However, such devices face a number of challenges due to the inability of electronic circuitry built on rigid silicon substrates to bend without breaking.

E-petal technology

To solve those issues, Zijian Zheng of the Hong Kong Polytechnic University, Feng Zhou of the Lanzhou Institute of Chemical Physics and their colleagues are have turned to the rose to create what they call “biomimicking topographic elastomeric petals,” or e-petals for short.

Using the surface topology of the rose petal, they have created a material that makes it possible for standard printed circuits to bend, stretch, and flex without snapping. They created elastomer layers which exhibit the same type of surface detail as the petal, creating a series of microscale craters with sharp ridges that can help stop cracks from forming, the website explained.

[STORY: Smell like a rose for hours with new perfume candy]

This method prevents rose petals from tearing, according to the researchers, and could act in a similar manner to allow electronic circuits to bend without breaking. When conducting materials such as metal, thin films are deposited on top and the ridges can essentially prevent tiny cracks from forming in the conducting layer, allowing it to show “remarkable stability,” they added.

Materials Views explains it in more technical terms: by using non-planar elastic substrates with topographical structures replicated from natural rose petals, Zheng and Zhou have come up with a material that can effectively stop crack propagation in the non-stretchable parts of flexible electronic device, regardless of the type of metals and conducting polymers used.

In fact, the properties of these printed circuits stayed consistent until the samples were stretched to 140 percent of their original size, and the components continued to function until they were stretched to 190 percent. This means that the e-petals could be used with traditional circuit printing, thus making the process of fabricating flexible circuitry easier and far less expensive.

“This work makes a very significant contribution in the field of omnidirectional stretchable and printable electronic devices,” the website added, “as it shows convincingly that the natural world can provide topographically structured materials of suitable length scales.” The potential uses for their e-petal technology include wearable devices, biomedical systems and robotics.

[STORY: Basis for electronics that stretch at the molecular level]

Last month, a team of South Korean researchers also tackled the issues of flexible technology, coming up with a way to make them less rigid by taking small pieces of bismuth ferrite (BiFeO3) and embedding them in flexible plastic polymers to create multiferroics materials with electronic properties that could be controlled by a magnetic field.

Their technique produced a thin, flexible film that, when tested, not only preserved the electric and magnetic properties of bismuth ferrite, but actually enhanced them. Furthermore, they found that the improved characteristics remained even when the film was curved into a cylinder, and also helped keep the devices from leaking current.

Gone are the days of breaking your phone when you sit on it, because stretchy phones and tablets are on the horizon.

—–

Follow redOrbit on Twitter, Facebook, Google+, Instagram and Pinterest.