Nav: Home

Making plastic more transparent while also adding electrical conductivity

July 06, 2020

In an effort to improve large touchscreens, LED light panels and window-mounted infrared solar cells, researchers at the University of Michigan have made plastic conductive while also making it more transparent.

They provide a recipe to help other researchers find the best balance between conductivity and transparency by creating a three-layer anti-reflection surface. The conductive metal layer is sandwiched between two "dielectric" materials that allow light to pass through easily. The dielectrics reduce the reflection from both the plastic and metal layer between them.

"We developed a way to make coatings with high transparency and conductivity, low haze, excellent flexibility, easy fabrication and great compatibility with different surfaces," said
Previously, Guo's team had shown that it was possible to add a layer of metal onto a plastic sheet to make it conductive--a very thin layer of silver that, by itself, reduced the transmission of light by roughly 10%.

Light transmission through plastic is a little lower than through glass, but its transparency can be improved with anti-reflection coatings. Guo and his colleague

"It was taken for granted that the transmittance of the conductor is lower than that of the substrate, but we show that this is not the case," said Chengang Ji, first author of the study in Nature Communications, who worked on the project as a Ph.D. student in electrical and computer engineering. Ji received his doctorate from U-M in 2019.

The dielectrics chosen by the team in this case are aluminum oxide and zinc oxide. On the side closest to the light source, the aluminum oxide reflects less light back to the source than the plastic surface would. Then comes the metal layer, composed of silver with a tiny amount of copper in it, just 6.5 nanometers thick, and then zinc oxide helps guide the light into the plastic surface. Some light still gets reflected back where the plastic meets the air on the opposite side, but overall, the light transmission is better than the plastic alone. The transmittance is 88.4%, up from 88.1% for the plastic alone.

With the theory results, the team anticipates that other researchers will be able to design similar sandwich-style flexible, highly transparent conductors, which allow even more light through than the plastic alone.

"We tell people how transparent a dielectric-metal-dielectric conductor could be, for a target electrical conductance. We also tell them how to achieve this high transmittance step-by-step," Liu said.

The tricks are selecting the right dielectrics and then figuring out the right thickness for each to suppress the reflection of the thin metal. In general, the material between the plastic and metal should have a higher refractive index, while the material nearest the display or light source should have a lower refractive index.

Guo is continuing to move the technology forward, collaborating on a project that uses transparent conductors in solar cells for mounting on windows. These could absorb infrared light and convert it to electricity while leaving the visible spectrum to brighten the room. He also proposes large panel interactive displays and car windshields that can melt ice the way rear windows can.
The research is funded by the MTRAC Advanced Materials Hub Award. Liu's visit to UM was supported by the National Natural Science Foundation of China

U-M has licensed the technology to the startup company

Guo is also a professor of mechanical engineering, macromolecular science and engineering, and applied physics. Ji is now a chief technology officer of another startup based on his Ph.D. work and Zhang, who was a former Ph.D. from Guo lab, is now a professor at Huazhong University of Science and Technology. Image link:

University of Michigan

Related Conductivity Articles:

Making plastic more transparent while also adding electrical conductivity
In an effort to improve large touchscreens, LED light panels and window-mounted infrared solar cells, researchers at the University of Michigan have made plastic conductive while also making it more transparent.
New high proton conductors with inherently oxygen deficient layers open sustainable future
Scientists at Tokyo Institute of Technology (Tokyo Tech) and the Australian Nuclear Science and Technology Organisation (ANSTO), discover a new family of high proton-conducting materials -- 'the hexagonal perovskite-related oxides' -- and shed light on the underlying mechanisms responsible for their conductivity.
Extremely low thermal conductivity in 1D soft chain structure BiSeX (X = Br, I)
Researchers found a new sort of simple one-dimensional (1D) crystal structured bismuth selenohalides (BiSeX, X = Br, I) with extremely low thermal conductivity.
Minimizing thermal conductivity of crystalline material with optimal nanostructure
Japanese researchers successfully minimized thermal conductivity by designing, fabricating, and evaluating the optimal nanostructure-multilayer materials through materials informatics (MI), which combines machine learning and molecular simulation.
Skoltech researchers use machine learning to aid oil production
Skoltech scientists and their industry colleagues have found a way to use machine learning to accurately predict rock thermal conductivity, a crucial parameter for enhanced oil recovery.
Scientists measured electrical conductivity of pure interfacial water
Skoltech scientists in collaboration with researchers from the University of Stuttgart, the Karlsruhe Institute of Technology and the Russian Quantum Center achieved the first systematic experimental measurements of the electrical conductivity of pure interfacial water, hence producing new results significantly extending our knowledge of interfacial water.
User research at BESSY II: How new materials increase the efficiency of direct ethanol fuel cells
A group from Brazil and an HZB team have investigated a novel composite membrane for ethanol fuel cells.
Atomic magnetometer points to better picture of heart conductivity
Mapping the electrical conductivity of the heart would be a valuable tool in diagnosis and disease management, but doing so would require invasive procedures, which aren't capable of directly mapping dielectric properties.
Quantum mechanical simulations of Earth's lower mantle minerals
The theoretical mineral physics group of Ehime University led by Dr.
Heat transport property at the lowermost part of the Earth's mantle
Lattice thermal conductivities of MgSiO3 bridgmanite and postperovskite (PPv) phases under the Earth's deepest mantle conditions were determined by quantum mechanical computer simulations.
More Conductivity News and Conductivity Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Sound And Silence
Sound surrounds us, from cacophony even to silence. But depending on how we hear, the world can be a different auditory experience for each of us. This hour, TED speakers explore the science of sound. Guests on the show include NPR All Things Considered host Mary Louise Kelly, neuroscientist Jim Hudspeth, writer Rebecca Knill, and sound designer Dallas Taylor.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

Kittens Kick The Giggly Blue Robot All Summer
With the recent passing of Ruth Bader Ginsburg, there's been a lot of debate about how much power the Supreme Court should really have. We think of the Supreme Court justices as all-powerful beings, issuing momentous rulings from on high. But they haven't always been so, you know, supreme. On this episode, we go all the way back to the case that, in a lot of ways, started it all.  Support Radiolab by becoming a member today at