Making computers and smartphones more energy efficient with novel tiny structures


nano makingcomput

With enhanced properties such as greater strength, lighter weight, increased electrical conductivity and chemical reactivity, nanomaterials (NMs) are widely used in areas like ICT, energy and medicine. For example, nanotubes, nanorods and nanowires with different size, structure and chemical composition have been successfully synthesised for various applications in mechanical, electromechanical, electric and optoelectronic devices.

Defined as materials with at least one external dimension sized between 1 nm and 100 nm, or with  measuring 100 nm or less, NMs play a crucial role in the next generation of mobile phones, computer chips, batteries, autonomous devices and robotics. Therefore, it’s important to know which set of structural and  for such materials gives the best performance for a particular application. Scientists and engineers are increasingly focusing on developing NMs that are highly energy efficient. But, the tinier NMs become, the harder it gets for them to manage the heat generated during the processing of information.

The EU-funded ENGIMA project has been addressing these issues. It was set up to explore “the structure-property relationships in the elaborated nanostructured multifunctional materials,” as noted on the project website. “It [ENGIMA] focuses on how to redistribute electricity efficiently at miniscule scales, harnessing nanotechnology breakthroughs that are opening up new possibilities and applications thought impossible until just a few years ago,” according to an article on the European Commission website.

As stated in the article, researchers involved with the project “developed a permanent static ‘negative ,’ a device thought impossible until about a decade ago. Previously proposed designs for negative capacitors worked on a temporary, transient basis but the ENGIMA-developed negative capacitor is the first to operate as a steady-state reversible device.” Capacitance refers to a measure of the amount of electric potential energy stored or separated for a given electric potential.

The same article adds: “The proposed approach harnesses properties of ferroelectric materials, which possess spontaneous polarization that can be reversed by an external electric field. Increasing the charge on the positive capacitor increases the voltage. The reverse occurs with the negative capacitor—its voltage drops as the charge increases.” The combination of the two capacitors “enables electricity to be distributed to regions of the circuit requiring higher voltage while the entire circuit operates at a lower voltage.” This is a crucial development because it helps tackle overheating problems affecting the performance of conventional computing circuits. “Building on this research, we are developing a practical platform for implementing ultra-low-power devices for information processing,” says ENGIMA lead researcher Igor Lukyanchuk.

Increasing the performance of processors means smartphones and various other electronic systems will become more energy efficient. Scheduled to end in late 2021, the ENGIMA (Engineering of Nanostructures with Giant Magneto-Piezoelectric and Multicaloric Functionalities) project will also help scientists design new nanostructures for future photovoltaic materials. “The results emerging from ENGIMA promise to open significant new opportunities and possibilities for high-tech industries, particularly in addressing current energy consumption and harvesting issues, with applications across many fields,” the European Commission article says.


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Novel nanostructures could make smartphones more efficient


More information: ENGIMA project website: www.engima.ferroix.net/
Provided by CORDIS

More Powerful Computing Possible from Ultra-thin memory storage device: University of Texas, Austin


ultrathinmemIllustration of a voltage-induced memory effect in monolayer nanomaterials, which layer to create “atomristors,” the thinnest memory storage device that could lead to faster, smaller and smarter computer chips. Credit: Cockrell School of Engineering, The University of Texas at Austin

Engineers worldwide have been developing alternative ways to provide greater memory storage capacity on even smaller computer chips. Previous research into two-dimensional atomic sheets for memory storage has failed to uncover their potential—until now.

A team of electrical engineers at The University of Texas at Austin, in collaboration with Peking University scientists, has developed the thinnest  device with dense  capacity, paving the way for faster, smaller and smarter computer chips for everything from consumer electronics to big data to brain-inspired computing.

“For a long time, the consensus was that it wasn’t possible to make memory devices from materials that were only one atomic layer thick,” said Deji Akinwande, associate professor in the Cockrell School of Engineering’s Department of Electrical and Computer Engineering. “With our new ‘atomristors,’ we have shown it is indeed possible.”

Made from 2-D nanomaterials, the “atomristors”—a term Akinwande coined—improve upon memristors, an emerging memory storage technology with lower memory scalability. He and his team published their findings in the January issue of Nano Letters.

“Atomristors will allow for the advancement of Moore’s Law at the system level by enabling the 3-D integration of nanoscale memory with nanoscale transistors on the same chip for advanced computing systems,” Akinwande said.

Memory storage and transistors have, to date, always been separate components on a microchip, but atomristors combine both functions on a single, more efficient computer system. By using metallic  (graphene) as electrodes and semiconducting atomic sheets (molybdenum sulfide) as the active layer, the entire memory cell is a sandwich about 1.5 nanometers thick, which makes it possible to densely pack atomristors layer by layer in a plane. This is a substantial advantage over conventional flash memory, which occupies far larger space. In addition, the thinness allows for faster and more efficient electric current flow.

Given their size, capacity and integration flexibility, atomristors can be packed together to make advanced 3-D chips that are crucial to the successful development of brain-inspired computing. One of the greatest challenges in this burgeoning field of engineering is how to make a memory architecture with 3-D connections akin to those found in the human brain.

“The sheer density of memory  that can be made possible by layering these synthetic atomic sheets onto each other, coupled with integrated transistor design, means we can potentially make computers that learn and remember the same way our brains do,” Akinwande said.

The research team also discovered another unique application for the technology. In existing ubiquitous devices such as smartphones and tablets, radio frequency switches are used to connect incoming signals from the antenna to one of the many wireless communication bands in order for different parts of a device to communicate and cooperate with one another. This activity can significantly affect a smartphone’s battery life.

The atomristors are the smallest radio frequency memory switches to be demonstrated with no DC battery consumption, which can ultimately lead to longer battery life.

“Overall, we feel that this discovery has real commercialization value as it won’t disrupt existing technologies,” Akinwande said. “Rather, it has been designed to complement and integrate with the silicon chips already in use in modern tech devices.”

 Explore further: A more efficient way to write data into non-volatile memory devices improves their performance

More information: Ruijing Ge et al, Atomristor: Nonvolatile Resistance Switching in Atomic Sheets of Transition Metal Dichalcogenides, Nano Letters (2017). DOI: 10.1021/acs.nanolett.7b04342