Phys.org August 13, 2021 Direct air carbon capture and storage (DACCS) is a comparatively new technology for removing carbon dioxide from the atmosphere. Since it would allow large amounts of CO2 to be trapped this technology could also reduce the greenhouse effect. To investigate how effectively this could be implemented with different system configurations of a certain process, researchers in Switzerland analyzed a total of five different configurations for capturing CO2 from the air and their use at eight different locations around the world. Autonomous system layouts prove to be a promising alternative, with a green house gases removal efficiency […]
Tag Archives: S&T Switzerland
Harvesting drinking water from humid air around the clock
Science Daily June 23, 2021 Researchers in Switzerland have designed and demonstrated a system that synergistically combines radiative shielding and cooling with a fully passive superhydrophobic condensate harvester, working with a coalescence-induced water removal mechanism. A shield, accounting for the atmospheric radiative heat, facilitates daytime atmospheric water harvesting under solar irradiation at realistic levels of relative humidity. The remarkable cooling power enhancement enables dew mass fluxes up to 50 g m−2 hour−1, close to the ultimate capabilities of such systems. The results demonstrate that the yield of related technologies can be at least doubled, while cooling and collection remain passive, […]
The biodegradable battery that’s 3D printed, disposable and made of paper
Phys.org June 3, 2021 A team of researchers in Switzerland developed and implemented the concept of a biodegradable electricity storage device. They developed gelatinous inks which consists of cellulose nanofibers and cellulose nanocrystallites, carbon in the form of carbon black, graphite and activated carbon. They used glycerin, water and two different types of alcohol to mix the ingredients and a pinch of table salt for ionic conductivity. They built a functioning supercapacitor from four layers of these ingredients flowing from a 3D printer one after the other: a flexible substrate, a conductive layer, the electrode and finally the electrolyte. The […]
Quantum electronics: ‘Bite’ defects in bottom-up graphene nanoribbons
Science Daily May 25, 2021 Researchers in Switzerland have shown the nature of the structural disorder in bottom-up zigzag graphene nanoribbons along with its effect on the magnetism and electronic transport based on scanning probe microscopies and first-principles calculations. They found that edge-missing m-xylene units emerging during the cyclodehydrogenation step of the on-surface synthesis are the most common point defects. These “bite” defects act as spin-1 paramagnetic centers, severely disrupting the conductance spectrum around the band extrema, and give rise to spin-polarized charge transport. They also showed that the electronic conductance across graphene nanoribbons is more sensitive to “bite” defects […]
New tech builds ultralow-loss integrated photonic circuits
Phys.org April 16, 2021 Researchers in Switzerland have developed a new technology for building silicon nitride integrated photonic circuits with record low optical losses and small footprints. They used Damascene process to make integrated circuits of optical losses of only 1 dB/m. Such low loss significantly reduces the power budget for building chip-scale optical frequency combs (“microcombs”), used in applications like coherent optical transceivers, low-noise microwave synthesizers, LiDAR, neuromorphic computing, and even optical atomic clocks. The team used the new technology to develop meter-long waveguides on 5×5 mm2 chips and high-quality-factor microresonators. They also report high fabrication yield, which is […]
Carbon-neutral ‘biofuel’ from lakes
Science Daily March 31, 2021 Although the greenhouse gas methane is less well known and much rarer in the atmosphere, its global warming potential is 80 to 100 times greater per unit. Methane from lakes and water reservoirs makes up about 20% of global natural methane missions. Researchers in Switzerland outline the potential and theoretical possibilities for using methane from lakes and other freshwater bodies for sustainable energy production. The feasibility of up-scaled adsorption-driven technologies to capture and refine aqueous Biogenic CH4 is mostly generated from biomass produced through atmospheric CO2 uptake. Its exploitation in freshwaters can thus secure large […]
Silicon waveguides move us closer to faster, light-based logic circuits
Phys.org February 8, 2021 Wiring up the transistors of an optical circuit with silicon waveguides is an important requirement to make compact, highly integrated chips. However, silicon is a strong absorber of visible light. To circumvent the absorption issue researchers in Switzerland used high contrast grating consisting of nanometer sized “posts” lined up in such a way that light passing through the posts interferes destructively with light passing between posts making sure that no light can “leak” through the grating. Most of the light gets reflected inside the waveguide. They showed that there was a loss of only 13 percent […]
New metamaterial offers reprogrammable properties
Science Daily January 22, 2021 Researchers in Switzerland have developed metamaterial made of silicon and magnetic powder which has a complicated structure that allows mechanical properties to vary. Each cell within the structure behaves like an electrical switch. It is possible to activate and deactivate individual cells by applying a magnetic field which modifies the internal state of the metamaterial, and consequently its mechanical properties. The programmable material is analogous to computer devices like hard drives. The devices contain bits of data that can be written to and read from in real time. The cells in this programmable metamaterial, called […]
Optical wiring for large quantum computers
Phy.org October 22, 2020 The fundamental qualities of individual trapped-ion qubits are promising for long-term systems, but the optics involved in their precise control are a barrier to scaling. Researchers in Switzerland used scalable optics co-fabricated with a surface-electrode ion trap to achieve high-fidelity multi-ion quantum logic gates, which are often the limiting elements in building up the precise, large-scale entanglement that is essential to quantum computation. Light is efficiently delivered to a trap chip in a cryogenic environment via direct fibre coupling on multiple channels, eliminating the need for beam alignment into vacuum systems and cryostats and lending robustness […]
Turning streetwear into solar power plants
Nanowerk October 22, 2020 Luminescent solar concentrators (LSCs) absorb diffusive light and increase the cost-effectiveness of solar cells; however, the compatibility with flexible photovoltaics and the energy transfer (ET) efficiency still require improvement. Researchers in Switzerland used amphiphilic polymer conetworks (APCNs) as polymer matrices for wearable LSCs owing to their flexibility and wearability. Furthermore, with the assistance of APCNs’ nanophase separated hydrophobic and hydrophilic domains, hydrophobic and hydrophilic luminescent materials were loaded in adjacent nanometer-separated domains. This resulted in high ET rates and broadened the acceptor’s absorption range, rendering a more efficient down conversion emission. The re-emitted photons indicated that […]