Existing nanofluidic approaches to facilitate the manipulation of ultra-small amounts of liquids usually require their confinement within quasi-1D nanochannels or nanopores. In these devices, the movement of the liquid objects must follow pre-designed routes. Researchers have now demonstrated a new platform for digital nanofluidics where water nanodroplets are trapped between a mica surface and graphene. Here, with the assistance of a graphene protection layer and ice-like lubricant monolayer, water nanodroplets can be moved, merged, separated, and patterned into regular arrays freely within a two-dimensional channel.
Concern about the depletion of global water resources has grown rapidly in the past decade due to our increasing global population and growing demand for other diverse applications. Since only 2.5% of the Earth's water is fresh, it has been reported that almost half of the world's population is at risk of a water crisis by the year 2025. Accordingly, significant research efforts have been focused on the desalination of brackish/seawater and the remediation and reuse of wastewater to meet the agricultural, industrial, and domestic water demands.
Individual graphene sheets and their functionalized derivatives have been used to remove metal ions and organic pollutants from water. These graphene-based nanomaterials show quite high adsorption performance as adsorbents. However they also cause additional cost because the removal of these adsorbent materials after usage is difficult and there is the risk of secondary environmental pollution unless the nanomaterials are collected completely after usage. One solution to this problem would be the assembly of individual sheets into three-dimensional (3D) macroscopic structures which would preserve the unique properties of individual graphene sheets, and offer easy collecting and recycling after water remediation.
By miniaturizing microbial fuel cells, it becomes possible to build miniature energy harvesters that could power lab-on-chip or point-of-care diagnostics devices independent of any external power source. Because micro-sized microbial fuel cells utilize less electrode area and less liquid fuel volume than their macro-sized counterparts, optimizing the electrodes and the fuel sources are the most important factors in designing a micro-sized MFC for maximum power production.
Stretchable energy storage and conversion devices are key components for the fabrication of complete and independent stretchable systems. A recent review summarizes the recent progresses in the developments of stretchable power sources including supercapacitors, batteries and solar cells. It discusses representative structural and material designs to impart stretchability to the originally rigid devices and analyze advantages and drawbacks associated with the various fabrication methods. It also presents summaries of the research progresses along with future development directions.
Ice accumulation is not just a cost and safety problem for the airline industry and other transportation areas, together with undesired environmental impacts. Here are some examples: Transmission lines and power network towers may deform or even collapse with the burden of excess amount of ice; ice accretion on wind turbine blades can cause a production loss as much as 50% of the annual production; frost and ice accumulation in refrigerators and heat exchangers results in a decrease of heat transfer efficiency. Therefore, great efforts have been made to understand the mechanism of icing and investigations on anti-icing and deicing have been extensively carried out. Various anti-icing and deicing methods have been developed such as for instance nanocoatings and other nanostructured surfaces.
The investigation of effects of engineered nanomaterials on endothelial cells - which form the inner lining of blood vessels - is a critical safety issue. Already, various engineered nanomaterials are being designed for biomedical applications for intravascular use and other nanomaterials may reach the vasculature as a result of occupational, environmental, or other types of exposure. Researchers have now elucidated the mechanism of cytotoxicity of carboxylated MWCNTs on cultured endothelial cells and they show a new potential way of pharmacological cytoprotection against cytotoxic effect of carboxylated MWCNTs.
Flexible electronics is a rising field in terms of research and potential application opportunities to obtain similar characteristics than today's prevailing rigid electronics components. In new work, researchers have demonstrated the semiconductor industry's most advanced device architecture - FinFET, a new generation of device architecture which Intel has adopted in 2011 in their microprocessors; these field effect transistors offer non-planar three-dimensional topology where the channels are vertically aligned in arrays of ultra-thin silicon fins bordered by multiple gates - in a flexible platform using only industry standard processes and keeping the advantages offered by silicon.