Nanowerk April 1, 2020 Graphene-based actuators featuring fast and reversible deformation under various external stimuli are promising for soft robotics. However, these bimorph actuators are incapable of complex and programmable 3D deformation, which limits their practical application. Researchers in China fabricated a moisture-responsive graphene actuator swarm that has programmable shape-changing capability by programming the SU-8 patterns underneath with specific geometries and orientations on a continuous graphene oxide film, forming a swarm of bimorph actuators. They achieved predictable and complex deformations including bending, twisting, coiling, asymmetric bending, 3D folding and the combination of them due to the collective coupling and coordination […]
How to Design a Perpetual Energy Machine
Quanta Magazine April 1, 2020 It is a tradition among puzzle columnists to pay homage to April Fools’ Day by testing the credulity of their readers with outrageous propositions. The late (and great) Martin Gardner, who authored the famous monthly column Mathematical Games in Scientific American for a quarter century, once used an April column to describe a thought experiment that purported to falsify the special theory of relativity. It was a version of the bar and ring paradox. Special relativity is still hale and hearty, but the thought experiment seems convincing at first glance. In the spirit of this […]
“Living drug factories” might treat diabetes and other diseases
MIT News March 30, 2020 To have a living drug factory that you can implant cells in patients, which could secrete drugs as-needed a team of researchers in the US (MIT, Boston Children’s Hospital, Joslin Diabetes Center, UMass Worcester) devised a way to protect the transplanted cells from the immune system by housing them inside a device built out of a silicon-based elastomer (polydimethylsiloxane) and a special porous membrane. The device contains a porous membrane that allows the transplanted cells to obtain nutrients and oxygen from the bloodstream but the pores are small enough so that immune cells such as […]
Novel graphene-based filters to make gas purification more effective
Nanowerk March 27, 2020 Precise molecular sieving is potentially possible using graphene oxide‐based membranes, if the porosity can be matched with the kinetic diameters of the gas molecules, which is possible via the tuning of graphene oxide interlayer spacing to take advantage of gas species interactions with graphene oxide channels. An international team of researchers (Australia, South Korea) have shown highly effective separation of gases from their mixtures by using uniquely tailored porosity in mildly reduced graphene oxide (rGO) based membranes. The study will lead to new avenues for the applications of graphene for efficiently separating CO2 from N2 and […]
Physicist from Hannover develops new photon source for tap-proof communication
EurekAlert March 27, 2020 Sources of entangled photons have been realized mainly in the near-infrared 700- to 1550-nm spectral window. Using custom-designed lithium niobate crystals for spontaneous parametric down-conversion and tailored superconducting nanowire single-photon detectors an international team of researchers (UK, Japan, Germany) has demonstrated two-photon interference and polarization-entangled photon pairs at 2090 nm. These results open the 2- to 2.5-μm mid-infrared window for the development of optical quantum technologies such as quantum key distribution in next-generation mid-infrared fiber communication systems and future Earth-to-satellite communications much more secure in the future….read more. Open Access TECHNICAL ARTICLE
Quantum copycat: Researchers find a new way in which bosons behave like fermions
Phys.org March 27, 2020 Researchers at Pennsylvania State University observed dynamical fermionization, where the momentum distribution of a T-G (Tonks-Girardeau) gas evolves from bosonic to fermionic after its axial confinement is removed. The asymptotic momentum distribution after expansion in one dimension is the distribution of rapidities, which are the conserved quantities associated with many-body integrable systems. Their measurements agree well with T-G gas theory. They also studied momentum evolution after the trap depth is suddenly changed to a new nonzero value, and we observed the theoretically predicted bosonic-fermionic oscillations…read more. TECHNICAL ARTICLE
Quantum-entangled light from a vibrating membrane
Phys.org March 31, 2020 Optical quantum states propagate with ultralow attenuation and resilient to ubiquitous thermal noise. Mechanical systems are envisioned as versatile interfaces between photons and a variety of solid-state quantm information processing platforms. Researchers in Denmark generated entanglement between two propagating optical modes by coupling them to the same cryogenic mechanical system. The entanglement persisted at room temperature. They verified the inseparability of the bipartite state and fully characterized its logarithmic negativity by homodyne tomography. Combined with quantum interfaces between mechanical systems and solid-state qubit processors, this paves the way for mechanical systems enabling long-distance quantum information networking […]
Researchers catch light in a funnel
Phys.org March 27, 2020 Rather than being an unavoidable nuisance, non-Hermiticity can be precisely controlled and used for sophisticated applications. Researchers in Germany implemented a non-Hermitian photonic mesh lattice by tailoring the anisotropy of the inter-site coupling. The appearance of an interface results in a complete collapse of the entire eigenmode spectrum, leading to an exponential localization of all modes at the interface. Consequently, any light field within the lattice travels toward this interface, irrespective of its shape and input position. Based on this topological phenomenon, they demonstrated a highly efficient funnel for light. The light accumulation achieved by the […]
Scientists electrify aluminum to speed up important process
Science Daily March 26, 2020 Researchers at Ohio State University describe how to shorten a process to turn one chemical — triphenylphosphine oxide — into another chemical — triphenylphosphine. They showed that the energy needed for the conversion can be generated by sending an electrical charge through an aluminum container. Doing so provides enough energy to allow aluminum to break one of the chemical bonds in triphenylphosphine oxide — essentially, to strip oxygen away from that molecule — and to leave behind just triphenylphosphine. The finding could make several industrial manufacturing processes cheaper and more efficient, make it easier to […]
Smaller scale solutions needed for rapid progress towards emissions targets
Science Daily April 2, 2020 Of the 45 energy technologies deemed critical by the International Energy Agency for meeting global climate targets, 38 need to improve substantially in cost and performance while accelerating deployment over the next decades. An international team of researchers (Austria, UK, Portugal, Canada) focus on the appropriate scale of technological responses in the energy system on the specific needs of accelerated low-carbon transformation, synthesize evidence on energy end-use technologies in homes, transport, and industry, as well as electricity generation and energy supply and go beyond technical and economic considerations to include innovation, investment, deployment, social, and […]