Science: Skin is flexible, durable, and sensitive to touch, which is transmitted by electrical signals. A team led by Zhenan Bao of Stanford University combined thin, flexible “epidermal electronics” with self-healing polymers to create a flexible conductive material that can restore its mechanical and electrical properties after being cut. Self-healing polymers are plastics that are able to reattach themselves after being cut. However, most such materials are not particularly conductive. Bao’s team solved that problem by adding nickel atoms to the polymer and letting electrons pass between the metal ions. To demonstrate the effectiveness of the new polymer, they used a scalpel to slice the material and then pressed the pieces together for 15 seconds. The material’s conductivity was 98% of what it had been prior to the separation, and the process could be repeated many times. There are some questions as to whether the material heals as well if it is twisted or torn apart instead of sliced, which only minimally deforms the material. Bao says her team’s next project will be attempting to make the material more elastic to make it even more skin-like.
BBC: One of the inventors of “transformation optics” has taken another step forward in the development of structures that can redirect light, hiding the objects behind them. David Smith of Duke University and his colleagues created a diamond-shaped structure that eliminates some of the imperfections of previous invisibility cloaks. The device was able to perfectly hide a 7.5-cm-diameter, 1-cm-tall cylinder from detection by microwaves. However, the cloak only worked from one direction. Microwaves from any other direction could see the cylinder. Because of the wavelength differences between microwaves and visible light, this doesn’t make invisibility to sight any more promising, but hiding objects from microwaves could be useful for the military and telecommunications.
Wall Street Journal: The Arctic and Antarctica are polar opposites, in more ways than one. Researchers at NASA’s Jet Propulsion Laboratory in Pasadena, California, and the British Antarctic Survey report this week in Nature Geoscience that in contrast to the extensive melting of Arctic sea ice in recent years, Antarctica has been experiencing record growth. From satellite data collected 1992–2010, they have determined that sea-ice cover in Antarctica has expanded slightly in area due to local winds: It grew in the areas of the ocean where the prevailing winds spread out the ice floes, and it shrank where winds blew ice floes up against the shoreline, writes Robert Lee Hotz for the Wall Street Journal. However, what is driving Antarctic wind patterns—and the larger connection to global climate change and warming—is not yet understood.
New York Times: Oxford energy policy professor Dieter Helm argues that although effective new energy technologies are being developed, what’s needed fundamentally “across Europe, the United States and China is a global agreement on a proper carbon price” that does not “discriminate between locations,” given the rise of coal planetwide. The US “is actually on a much better path than Europe,” thanks to a transition from coal to gas, investments in new technologies, and carbon emissions that are falling faster. But because present renewable-energy sources including wind and biofuels are inadequate, the planet will need new technologies while “slowing the coal juggernaut.” Sensible steps are to “tax carbon consumption (including imports); accelerate the switch from coal to gas; and support and finance” new solar, geothermal, nuclear, battery, and ocean-tidal technologies; smart grids; and electric cars.
New York Times: Legal scholar and former Obama administration official Cass R. Sunstein asserts, “Economists of diverse viewpoints concur that if the international community entered into a sensible agreement to reduce greenhouse gas emissions, the economic benefits would greatly outweigh the costs.” He invokes cost–benefit thinking that led President Ronald Reagan to make the US “the prime mover behind . . . the phasing out of ozone-depleting chemicals.” Sunstein argues that Reagan saw past Republican and conservative ridicule of concerned scientists and recognized the payoff in cancer avoidance alone. He quantifies prospective payoffs from auto fuel-economy mandates, claims that “monetary benefits dwarf the costs” of improving electrical appliance efficiency, and presumes a human-induced general increase in enormously costly hurricane intensity. He adds that “cost-effective” US climate measures ”should spur technological changes and regulatory initiatives” in foreign nations as well. “The big question now,” Sunstein says, “is whether today’s Republicans will follow Reagan’s example.”