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Category: engineering – Page 54

Emerging memristive neurons for neuromorphic computing and sensing

Inspired by the principles of the biological nervous system, neuromorphic engineering has brought a promising alternative approach to intelligence computing with high energy efficiency and low consumption. As pivotal components of neuromorphic system, artificial spiking neurons are powerful information processing units and can achieve highly complex nonlinear computations. By leveraging the switching dynamic characteristics of memristive device, memristive neurons show rich spiking behaviors with simple circuit. This report reviews the memristive neurons and their applications in neuromorphic sensing and computing systems. The switching mechanisms that endow memristive devices with rich dynamics and nonlinearity are highlighted, and subsequently various nonlinear spiking neuron behaviors emulated in these memristive devices are reviewed. Then, recent development is introduced on neuromorphic system with memristive neurons for sensing and computing. Finally, we discuss challenges and outlooks of the memristive neurons toward high-performance neuromorphic hardware systems and provide an insightful perspective for the development of interactive neuromorphic electronic systems.

Keywords: Memristive devices; artificial neurons; neuromorphic computing; neuromorphic sensing; spiking dynamics.

© 2023 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis Group.

Stimuli-Responsive Memristive Materials for Artificial Synapses and Neuromorphic Computing

Neuromorphic computing holds promise for building next-generation intelligent systems in a more energy-efficient way than the conventional von Neumann computing architecture. Memristive hardware, which mimics biological neurons and synapses, offers high-speed operation and low power consumption, enabling energy-and area-efficient, brain-inspired computing. Here, recent advances in memristive materials and strategies that emulate synaptic functions for neuromorphic computing are highlighted. The working principles and characteristics of biological neurons and synapses, which can be mimicked by memristive devices, are presented. Besides device structures and operation with different external stimuli such as electric, magnetic, and optical fields, how memristive materials with a rich variety of underlying physical mechanisms can allow fast, reliable, and low-power neuromorphic applications is also discussed. Finally, device requirements are examined and a perspective on challenges in developing memristive materials for device engineering and computing science is given.

Keywords: artificial synapses; memristive materials; neurons; synaptic plasticity.

© 2021 Wiley-VCH GmbH.

Bending the Rules of Solar: Novel Flexible Perovskite/Silicon Tandem Solar Cell Achieves Record Efficiency

A new study highlights the successful development of the first flexible perovskite/silicon tandem solar cell with a record efficiency of 22.8%, representing a major advance in flexible solar cell technology.

Although rigid perovskite/silicon tandem solar cells have seen impressive advancements, achieving efficiencies as high as 33.9%, the development of flexible versions of these cells has been limited. The main hurdle is improving light absorption in the ultrathin silicon bottom cells without compromising their mechanical flexibility.

In their pioneering study, a research team led by Dr. Xinlong Wang, Dr. Jingming Zheng, Dr. Zhiqin Ying, Prof. Xi Yang, and Prof. Jichun Ye from the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, has successfully demonstrated the first flexible perovskite/silicon tandem solar cell based on ultrathin silicon, with a thickness of approximately 30 µm. By reducing wafer thicknesses and adjusting the feature sizes of light-trapping textures, they significantly improved the flexibility of the silicon substrate without compromising light utilization. Additionally, by capping the perovskite top cells, they enhanced the mechanical durability of the device, thus addressing concerns related to fractures in the silicon surface.

Oops! Geoengineering Trick to Cool Brutal Heat Could Spike Temperature Elsewhere, Scientists Say

Researchers are warning that geoengineering efforts to help cool temperatures in California could trigger heatwaves in Europe, a “scary” implication given the sheer lack of regulation controlling such measures across the globe.

As The Guardian reports, scientists have suggested spraying aerosols into clouds over the ocean to cool down the surface below, a practice called “marine cloud brightening.” As the name suggests, the idea is to brighten clouds to make them reflect more of the Sun’s radiation back into space.

Last month, a team of University of Washington researchers attempted to do just that in the San Francisco Bay using a machine that sprays tiny sea-salt particles, amid criticism from environmentalists. The experiment was later shut down by city officials, citing health concerns.

Lockheed Martin and US Air Force Complete Flight Test of Intercontinental Ballistic Missile Reentry Vehicle

The Lockheed Martin and U.S. Air Force conducted a planned flight test of the unarmed, developmental Mk21A reentry vehicle in the Pacific Ocean on June 17. Mk21A is the U.S. Air Force’s integrated reentry vehicle and the critical front-end of the service’s future intercontinental ballistic missile (ICBM) weapon system. This flight test from Vandenberg Space Force Base in California, tested Lockheed Martin’s Mk21A design components and technologies for the vehicle. It also continues Lockheed Martin’s leadership and expertise in developing effective and reliable reentry vehicle technology.

This testing is done through Lockheed Martin’s Engineering and Manufacturing Development contract with the Air Force Nuclear Systems Center. Data collected during the event will further inform Mk21A design and future flight test activities. The company’s Mk21A program is on-schedule. Lockheed Martin is maturing its Mk21A design, which includes the arming and fuzing subsystem and support equipment, using advanced digital engineering tools, including advanced modeling and simulation. This allows for efficiency in schedule, reduced cost and risk, and increased confidence in system performance.

“This progress is built on a strong foundation—Lockheed Martin’s 65-plus years of demonstrated exceptional performance in reentry technologies and a pioneering digital engineering approach on this program from its beginning,” said Jay Watson, vice president of Strategic Reentry at Lockheed Martin. “We remain focused on delivering this capability for the warfighter as a trusted partner to the U.S. Air Force for ICBM reentry systems and modernization of the deterrent triad.”

Charge your Laptop in a Minute? Supercapacitors can help; new research offers clues

Imagine if your dead laptop or phone could charge in a minute or if an electric car could be fully powered in 10 minutes. While not possible yet, new research by a team of CU Boulder scientists could potentially lead to such advances.

Published today in the Proceedings of the National Academy of Sciences, researchers in Ankur Gupta’s lab discovered how ions, move within a complex network of minuscule pores. The breakthrough could lead to the development of more efficient energy storage devices, such as supercapacitors, said Gupta, an assistant professor of chemical and biological engineering.

“Given the critical role of energy in the future of the planet, I felt inspired to apply my chemical engineering knowledge to advancing energy storage devices,” Gupta said. “It felt like the topic was somewhat underexplored and, as such, the perfect opportunity.”

From Common White Powder to Quantum Innovation: Unlocking Nearly Noiseless Qubits

Researchers discovered that bismuth atoms embedded in calcium oxide can function as qubits for quantum computers, providing a low-noise, durable, and inexpensive alternative to current materials. This groundbreaking study highlights its potential to transform quantum computing and telecommunications.

Calcium oxide is an inexpensive, chalky chemical compound frequently used in the manufacturing of cement, plaster, paper, and steel. However, the common material may soon have a more high-tech application.

Scientists used theoretical and computational approaches to discover how tiny, lone atoms of bismuth embedded within solid calcium oxide can act as qubits — the building blocks of quantum computers and quantum communication devices. These qubits were described by University of Chicago Pritzker School of Molecular Engineering researchers and their collaborator in Sweden on June 6 in the scientific journal Nature Communications.

Revolutionary Rover Tech Tames Extreme Moon Temperatures

A team from Nagoya University invented a heat-switch device for lunar rovers to withstand the Moon’s extreme temperatures. The technology optimizes thermal control, alternating between cooling and insulating, facilitating longer missions with less energy.

Astronauts navigating the moon’s terrain in a vehicle contend with not only the perils of zero gravity and potential crater falls, but also drastic temperature swings. The moon’s climate ranges from searing highs of 127°C (260°F) to bone-chilling lows of −173°C (−280°F).

Team from Nagoya University in Japan developed a heat-switch device designed to enhance the durability of lunar rovers. Their collaborative research with the Japan Aerospace Exploration Agency was featured in the journal Applied Thermal Engineering.

Voyager 1 Returning Science Data From All Four Instruments

Most distant spacecraft, #Voyager1, is now returning data from all four science instruments for the first time following a technical issue last November.

NASA’s Voyager 1 spacecraft is conducting normal science operations for the first time following a technical issue that arose in November 2023.

The team partially resolved the issue in April when they prompted the spacecraft to begin returning engineering data, which includes information about the health and status of the spacecraft. On May 19, the mission team executed the second step of that repair process and beamed a command to the spacecraft to begin returning science data. Two of the four science instruments returned to their normal operating modes immediately. Two other instruments required some additional work, but now, all four are returning usable science data.

The four instruments study plasma waves, magnetic fields, and particles. Voyager 1 and Voyager 2 are the only spacecraft to directly sample interstellar space, which is the region outside the heliosphere — the protective bubble of magnetic fields and solar wind created by the Sun.

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