Phys.org February 28, 2022 Previously researchers in Japan synthesized multiblock copolymers that exhibited excellent elasticity and self-healing by using the two-component copolymerization of non-polar ethylene and polar methoxyaryl-substituted propylenes. Now they have developed a three-component ‘terpolymer’ of ethylene and two different methoxyaryl-functionalized propylenes using a scandium catalyst. The long, soft sections form a highly flexible matrix, within which are hard and crystalline sections that rapidly re-aggregate after the material is cut, thereby self-healing any damage within five minutes to recover 99% of its toughness and 97% of its tensile strength. The material could be stretched to almost 14 times its […]
Tag Archives: S&T Japan
Towards self-sensing soft robots with electrochemically driven pumps
Science Daily February 8, 2022 Researchers in Japan based the electrochemical dual transducer (ECDT) design on the electrohydrodynamic (EHD) pump they had previously designed. The pump consisted of a symmetrical arrangement of planar electrodes, which allowed easy control of the flow direction by simply changing the voltage. The arrangement enabled an obstruction-free even flow in each direction due to the same strength of the electric field on either side. They evaluated sensing performance in terms of range of detectable flow, rate, sensitivity, response, and relaxation times, and used mathematical modeling to understand the sensing mechanism. The ECDT does not require […]
Scientists weave atomically thin wires into ribbons
Phys.org January 31, 2022 Using tungsten telluride nanowires researchers in Japan created bundles of wires deposited on a flat substrate and exposed to vapors of chalcogens like sulfur, selenium, and tellurium. With a combination of heat and vapor, the initially separate threads in the bundles were successfully woven together into narrow, atomically thin nanoribbons with a characteristic zigzag structure. By tuning the thickness of the original bundles, they could even choose whether these ribbons were oriented parallel to the substrate or perpendicular to it. By tuning the substrate on which the bundles are placed, they could control whether the ribbons […]
Development of a lithium-air battery with an energy density over 500 wh/kg
Science Daily January 20, 2022 Lithium–air batteries (LABs) are potential candidates for next-generation rechargeable batteries because of their extremely high theoretical energy density. However, the reported values for the actual energy density of LABs are much lower than those for lithium batteries, mainly due to the excess amount of electrolyte in the cell. In the present review article, researchers in Japan estimated the practical energy density for the representative LABs reported in academia, and the critical factors for improving the energy density of LABs are summarized. The criteria for evaluating LABs in laboratory-based experiments are also proposed for accurately predicting […]
Scientists reduce all-solid-state battery resistance by heating
Science Daily January 7, 2022 The interface between the positive electrode and solid electrolyte in an all-solid state battery shows a large electrical resistance, and the resistance increases when the electrode surface is exposed to air, degrading the battery capacity and performance. Researchers in Japan demonstrated that drastic reduction of the resistance is achievable by annealing the entire battery cell. Exposing the LiCoO2 positive electrode surface to H2O vapor increases the resistance by more than 10 times (to greater than 136 Ω cm2). The magnitude can be reduced to the initial value (10.3 Ω cm2) by annealing the sample in […]
Scientists successfully manipulate a single skyrmion at room temperature
Nanowerk December 17, 2021 The key to creating spintronics devices is the ability to effectively manipulate, and measure, a single skyrmion. Researchers in Japan used a thin magnetic plate made up of a compound of cobalt, zinc, and manganese, Co9Zn9Mn2 to observe the dynamics of a single skyrmion at room temperature. They were able to track the motions of the skyrmion and control its Hall motion directions by flipping the magnetic field when they subjected it to ultrafast pulses of electric current—on the scale of nanoseconds. They found that the skyrmion’s motion demonstrated a dynamic transition from a pinned static […]
Tsunamis’ magnetic fields are detectable before sea level change
Phys.org December 21, 2021 The motion of conductive seawater by tsunamis can generate magnetic fields in the presence of the background geomagnetic main field. Previous studies found that, using the tsunami-generated seafloor magnetic field, it is possible to predict the propagation direction and wave height prior to the actual arrivals of tsunamis. In this study researchers in Japan correlate the tsunami magnetic field and the tsunami sea level change using observed data and three-dimensional simulations of the 2009 Samoa and 2010 Chile tsunamis. Their direct comparison of the tsunami observed magnetic field and tsunami sea level change illustrated that the […]
Scientists successfully manipulate a single skyrmion at room temperature
Nanowerk November 24, 2021 The key to creating spintronics devices is the ability to effectively manipulate, and measure, a single tiny vortex. Researchers in Japan used a thin magnetic plate made up of a compound of cobalt, zinc, and manganese which is known as a chiral-lattice magnet. They directly observed the dynamics of a single skyrmion at room temperature and tracked the motions of the skyrmion and control its Hall motion directions by flipping the magnetic field when they subjected it to ultrafast pulses of electric current—on the scale of nanoseconds. They found that the skyrmion’s motion demonstrated a dynamic […]
Towards self-restoring electronic devices with long DNA molecules
Science Daily November 2, 2021 single-molecule conductance falls off sharply with the length of the molecule so that only extremely short stretches of DNA are useful for electrical measurements. Researchers in Japan achieved an unconventionally high conductivity with a long DNA molecule-based junction in a “zipper” configuration that also shows a remarkable self-restoring ability under electrical failure. The team used a 10-mer and a 90-mer DNA strand to form a zipper-like structure and attached them to either a gold surface or to the metal tip of a scanning tunneling microscope. The separation between the tip and the surface constituted the […]
On-water creation of conducting MOF nanosheets
Science Daily October 28, 2021 Researchers in Japan have created functional materials with advanced three-dimensional nanostructures that conduct electricity based on the idea that unique reactions occur at interfaces of water and oil. As they spread a solution containing organic linkers on aqueous solution of metal ions the substances begin assembling their components in a hexagonal arrangement forming nanosheets where the liquid and air meet. They used two barriers to compress the nanosheets into more dense and continuous state. The process produced thin nanosheets with highly organized crystalline structures, tightly ordered crystals also indicated the electrical properties of the material. […]