Tag Archives: Shandong University

Improving fossil-fueled cars’ efficiency with graphene-based ballistic rectifier

UK and Chinese researchers have a developed a technology to make fuel use more efficient in fossil-fueled cars (from a June 2, 2016 news item on phys.org),

A graphene-based electrical nano-device has been created which could substantially increase the energy efficiency of fossil fuel-powered cars.

The nano-device, known as a ‘ballistic rectifier’, is able to convert heat which would otherwise be wasted from the car exhaust and engine body into a useable electrical current.

Parts of car exhausts can reach temperatures of 600 degrees Celsius. The recovered energy can then be used to power additional automotive features such as air conditioning and power steering, or be stored in the car battery.

The nano-rectifier was built by a team at The University of Manchester led by Professor Aimin Song and Dr. Ernie Hill, with a team at Shandong University. The device utilises graphene’s phenomenally high electron mobility, a property which determines how fast an electron can travel in a material and how fast electronic devices can operate.

A June 1, 2016 University of Manchester press release, which originated the news item, provides more detail,

The resulting device is the most sensitive room-temperature rectifier ever made. Conventional devices with similar conversion efficiencies require cryogenically low temperatures.

Even today’s most efficient internal combustion engines can only convert about 70% of energy burned from fossil fuels into the energy required to power a car. The rest of the energy created is often wasted through exhaust heat or cooling systems.

Greg Auton, who performed most of the experiment said: “Graphene has exceptional properties; it possesses the longest carrier mean free path of any electronic material at room temperature.

“Despite this, even the most promising applications to commercialise graphene in the electronics industry do not take advantage of this property. Instead they often try to tackle the the problem that graphene has no band gap.”

Professor Song who invented the concept of the ballistic rectifier said: “The working principle of the ballistic rectifier means that it does not require any band gap. Meanwhile, it has a single-layered planar device structure which is perfect to take the advantage of the high electron-mobility to achieve an extremely high operating speed.

“Unlike conventional rectifiers or diodes, the ballistic rectifier does not have any threshold voltage either, making it perfect for energy harvest as well as microwave and infrared detection”.

The Manchester-based group is now looking to scale up the research by using large wafer-sized graphene and perform high-frequency experiments. The resulting technology can also be applied to harvesting wasted heat energy in power plants.

Rice University collaborates with Shandong University on a Joint Center for Carbon Nanomaterials

They’re not billing this as a joint US-China project but with Rice University being in Texas, US and Shandong University being in Shandong (province) in China, I think it’s reasonable to describe it that way. Here’s more about the project from a Feb. 4, 2015 news item on Azonano,

Scientists from Rice University and Shandong University, China, celebrated the opening of the Joint Center for Carbon Nanomaterials, a collaborative facility to study nanotechnology, on Feb. 1 [2015].

Rice faculty members Pulickel Ajayan and Jun Lou, the chair and associate chair, respectively, of the university’s Department of Materials Science and NanoEngineering, took part in the ceremony along with Rice alumnus Lijie Ci, director of the new center and a professor of materials science and engineering at Shandong. The center’s dedication was part of the first International Workshop on Engineering and Applications of Nanocarbon, held Jan. 31-Feb. 2 [2015].

Determining where this new center is located proved to be a challenge. From a Feb. 2, 2015 Rice University news release, which originated the news item,

“We at Rice University are excited and honored to collaborate with Shandong University on this important endeavor,” Rice President David Leebron said in a message recorded for the ceremony. [emphasis mine] “The center represents and combines two very important initiatives for Rice: research excellence and applications in nanosciences and long-term partnerships with the best institutions worldwide.”

“A lot of people are working on carbon nanoscience on both campuses, and we expect they will be interested in taking part,” Ajayan said. “Nanotubes and graphene are essentially the building blocks for the center, but Lijie wants to build ecologically relevant, applied research that can be commercialized. That’s the long-term goal. All of the experience we have had in the area will be beneficial.”

Ajayan expects students from both universities will travel. “People from Rice will be engaged in some of the activities of this joint center, including advising students there. And we hope Shandong students will have the opportunity to come to Rice for a short time,” he said. “The center also contributes to Rice’s goal to build closer connections with China.” [emphases mine]

Ajayan and Ci came to Rice together in 2007 from Rensselaer Polytechnic Institute; Ajayan was a faculty member and Ci was a postdoctoral researcher. At Rice, they introduced the darkest material ever measured at the time of its invention in 2008, an accomplishment that landed them in the Guinness Book of World Records.

They also collaborated on the first two-dimensional material to incorporate graphene and hexagonal boron nitride in a seamless lattice. Such 2-D materials have since become the focus of worldwide research for their potential as electronic components. And Ci, Lou and Ajayan worked together to study the nanoscale friction properties of carbon nanotubes.

I’m inferring from the portions I’ve highlighted that this center is located at Shandong University.