Transplacental Transmission of Porcine Epidemic Diarrhea Virus.

Because the porcine epidemic diarrhea virus (PEDV) is a critical pathogen resulting in rapid spreading and high mortality rates in piglets, understanding of the transmission route of PEDV is required for its controlling. Until now, it is well known that PEDV transmission routes are various, such as fecal-oral route, contaminated feed, farmworkers, and transport vehicles. However, unlike several swine-infected viruses, there were no reports of vertical transmission with PEDV. In our study, we confirmed possible vertical transmission of PEDV. We confirmed PEDV in piglet testicles and umbilical cords from PEDV-positive sow. These findings are direct evidence that PEDV is transmitted vertically through placenta. This is the first report on transplacental transmission of PEDV and will be very important information for controlling PED.

Stretchable organic optoelectronic sensorimotor synapse.

Emulation of human sensory and motor functions becomes a core technology in bioinspired electronics for next-generation electronic prosthetics and neurologically inspired robotics. An electronic synapse functionalized with an artificial sensory receptor and an artificial motor unit can be a fundamental element of bioinspired soft electronics. Here, we report an organic optoelectronic sensorimotor synapse that uses an organic optoelectronic synapse and a neuromuscular system based on a stretchable organic nanowire synaptic transistor (s-ONWST). The voltage pulses of a self-powered photodetector triggered by optical signals drive the s-ONWST, and resultant informative synaptic outputs are used not only for optical wireless communication of human-machine interfaces but also for light-interactive actuation of an artificial muscle actuator in the same way that a biological muscle fiber contracts. Our organic optoelectronic sensorimotor synapse suggests a promising strategy toward developing bioinspired soft electronics, neurologically inspired robotics, and electronic prostheses.

Tuning anhydrous proton conduction in single-ion polymers by crystalline ion channels.

The synthesis of high-conductivity solid-state electrolyte materials with eliminated polarization loss is a great challenge. Here we show a promising potential of single-ion block copolymers with crystalline protogenic channels as efficient proton conductors. Through the self-organization of zwitterion, imidazole, and polystyrene sulfonate with controlled dipolar interactions therein, the distance between neighboring proton donors and acceptors in ionic crystals, as well as the dipolar orientation in nanoscale ionic phases was precisely tuned. This allowed a markedly high static dielectric constant comparable to water and fast structural diffusion of protons with a low potential barrier for single-ion polymers. The optimized sample exhibited a high proton diffusion coefficient of 2.4 × 10-6 cm2 s-1 under anhydrous conditions at 90 °C.

Low-voltage-driven soft actuators.

Soft actuators based on electroactive polymers (EAPs) are the core constituents of future soft robots owing to their fascinating properties such as lightweight, compactness, easy fabrication into various forms, and low cost. Ionic EAP actuators are particularly attractive owing to the low driving voltages (<3 V) as compared to those of electronic EAP actuators (usually kilovolts). This paper presents a brief overview of the recent progress in a range of EAP actuators by focusing on low voltage operation, in addition to the challenges and future strategies for their wide applicability in artificial muscles and various innovative soft robot technologies.

True Low-Power Self-Locking Soft Actuators.

Natural double-layered structures observed in living organisms are known to exhibit asymmetric volume changes with environmental triggers. Typical examples are natural roots of plants, which show unique self-organized bending behavior in response to environmental stimuli. Herein, light- and electro-active polymer (LEAP) based actuators with a double-layered structure are reported. The LEAP actuators exhibit an improvement of 250% in displacement and hold an object three times heavier as compared to that in the case of conventional electro-active polymer actuators. Most interestingly, the bending motion of the LEAP actuators can be effectively locked for a few tens of minutes even in the absence of a power supply. Further, the self-locking LEAP actuators show a large and reversible bending strain of more than 2.0% and require only 6.2 mW h cm-2 of energy to hold an object for 15 min at an operating voltage of 3 V. These novel self-locking soft actuators should find wide applicability in artificial muscles, biomedical microdevices, and various innovative soft robot technologies.

One-volt-driven superfast polymer actuators based on single-ion conductors.

The key challenges in the advancement of actuator technologies related to artificial muscles include fast-response time, low operation voltages and durability. Although several researchers have tackled these challenges over the last few decades, no breakthrough has been made. Here we describe a platform for the development of soft actuators that moves a few millimetres under 1 V in air, with a superfast response time of tens of milliseconds. An essential component of this actuator is the single-ion-conducting polymers that contain well-defined ionic domains through the introduction of zwitterions; this achieved an exceptionally high dielectric constant of 76 and a 300-fold enhancement in ionic conductivity. Moreover, the actuator demonstrated long-term durability, with negligible changes in the actuator stroke over 20,000 cycles in air. Owing to its low-power consumption (only 4 mW), we believe that this actuator could pave the way for cutting-edge biomimetic technologies in the future.

Ion Transport in Nanostructured Phosphonated Block Copolymers Containing Ionic Liquids.

The morphology and conductivity of poly(styrenephosphonate-b-methylbutylene) block copolymers containing ionic liquids are investigated. The block copolymers display a series of well-defined self-assembled morphologies, i.e., lamellae, gyroid, hexagonal cylinder (HEX), body-centered cubic, and A15 lattice, in the absence and presence of ionic liquids. The observation of an equilibrium A15 lattice for linear diblock copolymers, in contrast to a number of theoretical studies, is ascribed to the packing frustration accompanied by prevailing electrostatic interactions. The samples having the A15 lattice show a substantially higher morphology factors (0.83-0.96) than those with the HEX phases (0.42-0.69). This indicates the structural advantage of the A15 lattice with a well-defined 3D symmetry over the 2D HEX structure for constructing less tortuous ion-conduction pathways. This unprecedented study portends the rational design of nanostructured phosphonated polymer membranes with improved conductivity.

Synthesis of three-dimensionally interconnected sulfur-rich polymers for cathode materials of high-rate lithium-sulfur batteries.

Elemental sulfur is one of the most attractive cathode active materials in lithium batteries because of its high theoretical specific capacity. Despite the positive aspect, lithium-sulfur batteries have suffered from severe capacity fading and limited rate capability. Here we report facile large-scale synthesis of a class of organosulfur compounds that could open a new chapter in designing cathode materials to advance lithium-sulfur battery technologies. Porous trithiocyanuric acid crystals are synthesized for use as a soft template, where the ring-opening polymerization of elemental sulfur takes place along the thiol surfaces to create three-dimensionally interconnected sulfur-rich phases. Our lithium-sulfur cells display discharge capacity of 945 mAh g(-1) after 100 cycles at 0.2 C with high-capacity retention of 92%, as well as lifetimes of 450 cycles. Particularly, the organized amine groups in the crystals increase Li(+)-ion transfer rate, affording a rate performance of 1210, mAh g(-1) at 0.1 C and 730 mAh g(-1) at 5 C.

Phosphinite-Ni(0) mediated formation of a phosphide-Ni(II)-OCOOMe species via uncommon metal-ligand cooperation.

Reversible transformations are observed between a phosphide-nickel(II) alkoxide and a phosphinite-nickel(0) species via a P-O bond formation coupled with a 2-e(-) redox change at the nickel center. In the forward reaction, the nickel(0) dinitrogen species (PP(OMe)P)Ni(N2) (2) and {(PP(OMe)P)Ni}2(µ-N2) (3) were formed from the reaction of (PPP)NiCl (1) with a methoxy anion. In the backward reaction, a (PPP)Ni(II) moiety was regenerated from the CO2 reaction of 3 with the concomitant formation of a methyl carbonate ligand in (PPP)Ni(OCOOMe) (7). Thus, unanticipated metal-ligand cooperation involving a phosphide based ligand is reported.

Fast low-voltage electroactive actuators using nanostructured polymer electrolytes.

Electroactive actuators have received enormous interest for a variety of biomimetic technologies ranging from robotics and microsensors to artificial muscles. Major challenges towards practically viable actuators are the achievement of large electromechanical deformation, fast switching response, low operating voltage and durable operation. Here we report a new electroactive actuator composed of self-assembled sulphonated block copolymers and ionic liquids. The new actuator demonstrated improvements in actuation properties over other polymer actuators reported earlier, large generated strain (up to 4%) without any signs of back relaxation. In particular, the millimetre-scale displacements obtained for the actuators, with rapid response (<1 s) at sub-1-V conditions over 13,500 cycles in air, have not been previously reported in the literature. The key to success stems from the evolution of the unique hexagonal structure of the polymer layer with domain size gradients beneath the cathode during actuation, which promotes the bending motion of the actuators.

Blue-emitting self-assembled polymer electrolytes for fast, sensitive, label-free detection of Cu(II) ions in aqueous media.

We have developed a light-emitting material based on nonconjugated block copolymers that contain polystyrene sulfonate (PSS) chains. The confinement of the PSS chains within nanosized domains appeared to be a powerful means of achieving enhanced fluorescence signals. High fluorescence quantum yield, with a maximum value of 37%, was obtained by adjusting the types of self-assembled morphologies of PSS-containing block copolymers; in contrast, the fluorescence quantum yield was merely 5% for the PSS homopolymer lacking organization. The wavelength of fluorescence emission was tunable by rational molecular design. In addition, significant self-quenching behavior was not noticed in diverse forms of this material such as solutions, thin films, and free-standing membranes. Notably, the light-emitting self-assembled block copolymer electrolytes exhibited high sensitivity toward Cu(2+) ions, with a detection limit of parts per billion levels, rapid response time of ≤1 min, and insignificant interference of other competitive metal ions.