Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: engineering – Page 194

New technique increases 3D printing speed by 1,000 to 10,000 times

Any comments?

Ultraprecise 3D printing technology is a key enabler for manufacturing precision biomedical and photonic devices. However, the existing printing technology is limited by its low efficiency and high cost. Professor Shih-Chi Chen and his team from the Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong (CUHK), collaborated with the Lawrence Livermore National Laboratory to develop the Femtosecond Projection Two-photon Lithography (FP-TPL) printing technology.

By controlling the spectrum via temporal focusing, the laser 3D printing process is performed in a parallel layer-by-layer fashion instead of point-by-point writing. This new technique substantially increases the printing speed by 1,000—10,000 times, and reduces the cost by 98 percent. The achievement has recently been published in Science, affirming its technological breakthrough that leads nanoscale 3D printing into a new era.

The conventional nanoscale 3D , i.e., two-photon polymerization (TPP), operates in a point-by-point scanning fashion. As such, even a centimeter-sized object can take several days to weeks to fabricate (build rate ~ 0.1 mm3/hour). The process is time-consuming and expensive, which prevents practical and industrial applications. To increase speed, the resolution of the finished product is often sacrificed. Professor Chen and his team have overcome the challenging problem by exploiting the concept of temporal focusing, where a programmable femtosecond light sheet is formed at the focal plane for parallel nanowriting; this is equivalent to simultaneously projecting millions of laser foci at the , replacing the traditional method of focusing and scanning laser at one point only. In other words, the FP-TPL technology can fabricate a whole plane within the time that the point-scanning system fabricates a point.

Physicists determine the barely-measurable property entropy for the first time in complex plasmas

Since the end of the 19th century, physicists have known that the transfer of energy from one body to another is associated with entropy. It quickly became clear that this quantity is of fundamental importance, and so began its triumphant rise as a useful theoretical quantity in physics, chemistry and engineering. However, it is often very difficult to measure. Professor Dietmar Block and Frank Wieben of Kiel University (CAU) have now succeeded in measuring entropy in complex plasmas, as they reported recently in the renowned scientific journal Physical Review Letters. In a system of charged microparticles within this ionized gas, the researchers were able to measure all positions and velocities of the particles simultaneously. In this way, they were able to determine the entropy, as it was already described theoretically by the physicist Ludwig Boltzmann around 1880.

Surprising thermodynamic equilibrium in plasma

“With our experiments, we were able to prove that in the important model system of complex , the thermodynamic fundamentals are fulfilled. What is surprising is that this applies to microparticles in a plasma, which is far away from thermodynamic equilibrium,” explains Ph.D. student Frank Wieben. In his experiments, he is able to adjust the thermal motion of the microparticles by means of a laser beam. Using video microscopy, he can observe the dynamic behaviour of the particles in real time, and determine the from the information collected.

I’m definitely not worried about the AI Apocalypse: John Giannandrea

John Giannandrea, Vice President of Engineering with responsibility for Google’s Computer Science Research and Machine Intelligence groups; leading teams in Machine Learning, Machine Intelligence, Computer Perception, Natural Language Understanding, and Quantum Computing, “I’m definitely not worried about the AI apocalypse, I just object to the hype and soundbites that some people are making” said at the TechCrunch Disrupt conference in San Francisco.

Google’s John Giannandrea sits down with Frederic Lardinois to discuss the AI hype/worry cycle and the importance, limitations, and acceleration of machine learning.

First commercial electric plane takes flight in Canada

The world’s first fully electric commercial aircraft took its inaugural test flight on Tuesday, taking off from the Canadian city of Vancouver and offering hope that airlines may one day end their polluting emissions.

“This proves that commercial aviation in all-electric form can work,” said Roei Ganzarski, chief executive of Seattle-based engineering firm magniX.

The company designed the plane’s motor and worked in partnership with Harbour Air, which ferries half a million passengers a year between Vancouver, Whistler ski resort and nearby islands and coastal communities.

In surprise breakthrough, scientists create quantum states in everyday electronics

After decades of miniaturization, the electronic components we’ve relied on for computers and modern technologies are now starting to reach fundamental limits. Faced with this challenge, engineers and scientists around the world are turning toward a radically new paradigm: quantum information technologies.

Quantum technology, which harnesses the strange rules that govern particles at the , is normally thought of as much too delicate to coexist with the electronics we use every day in phones, laptops and cars. However, scientists with the University of Chicago’s Pritzker School of Molecular Engineering announced a significant breakthrough: Quantum states can be integrated and controlled in commonly used made from silicon carbide.

“The ability to create and control high-performance quantum bits in commercial electronics was a surprise,” said lead investigator David Awschalom, the Liew Family Professor in Molecular Engineering at UChicago and a pioneer in quantum technology. “These discoveries have changed the way we think about developing quantum technologies—perhaps we can find a way to use today’s electronics to build quantum devices.”

Electro-optical device provides solution to faster computing memories and processors

The first ever integrated nanoscale device which can be programmed with either photons or electrons has been developed by scientists in Harish Bhaskaran’s Advanced Nanoscale Engineering research group at the University of Oxford.

In collaboration with researchers at the universities of Münster and Exeter, scientists have created a first-of-a-kind electro– which bridges the fields of optical and electronic computing. This provides an elegant solution to achieving faster and more energy efficient memories and processors.

Computing at the has been an enticing but elusive prospect, but with this development it’s now in tangible proximity. Using light to encode as well as transfer information enables these processes to occur at the ultimate speed limit—that of light. While as of recently, using light for certain processes has been experimentally demonstrated, a compact device to interface with the electronic architecture of traditional computers has been lacking. The incompatibility of electrical and light-based computing fundamentally stems from the different interaction volumes that electrons and photons operate in. Electrical chips need to be small to operate efficiently, whereas need to be large, as the wavelength of light is larger than that of electrons.

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that painstakingly organized chaos, in temperatures millions of times colder than interstellar space, Kang-Kuen Ni achieved a feat of precision. Forcing two ultracold molecules to meet and react, she broke and formed the coldest bonds in the history of molecular couplings.

“Probably in the next couple of years, we are the only lab that can do this,” said Ming-Guang Hu, a postdoctoral scholar in the Ni lab and first author on their paper published today in Science. Five years ago, Ni, the Morris Kahn Associate Professor of Chemistry and Chemical Biology and a pioneer of ultracold chemistry, set out to build a new apparatus that could achieve the lowest temperature of any currently available technology. But they couldn’t be sure their intricate engineering would work.

Now, they not only performed the coldest reaction yet, they discovered their new apparatus can do something even they did not predict. In such intense cold—500 nanokelvin or just a few millionths of a degree above absolute zero—their slowed to such glacial speeds, Ni and her team could see something no one has been able to see before: the moment when two molecules meet to form two new molecules. In essence, they captured a reaction in its most critical and elusive act.

Ant-based troll detection

Uncovering trolls and malicious or spammy accounts on social media is increasingly difficult as the miscreants find more and more ways to camouflage themselves as seemingly legitimate. Writing in the International Journal of Intelligent Engineering Informatics, researchers in India have developed an algorithm based on ant-colony optimization that can effectively detect accounts that represent a threat to normal users.

Asha Kumari and Balkishan Department of Computer Science and Applications at Maharshi Dayanand University, in Rohtak, India, explain that the connections between twitter users are analogous to the pheromone chemical communication between ants and this can be modeled in an based on how ant colonies behave to reveal the strongest connections in the twitter network and so uncover the accounts that one might deem as threatening to legitimate users.

The team’s tests on their system were successful in terms of precision, recall, f-measure, true-positive rate, and false-positive rate based on 26 features examined by the system played against almost 41,500 user accounts attracted to honeypots. Moreover, they report that the approach is superior to existing techniques. The team adds that they hope to be able to improve the system still further by adding so-called machine learning into the algorithm so that it can be trained to better identify threatening accounts based on data from known threats and legitimate accounts.

/* */