Category Chemistry/Nanotechnology

Developing a Gel-Based Sensor Using Crystal Morphology Prediction

A new molecular gel recipe developed at the University of Michigan is at the core of a prototype for a more accurate lead paint test to see whether a paint chip contains >5,000 parts per million of the poisonous metal that was banned from pigments in 1978. Government agencies use that threshold to define paint as “lead-based” and the EPA requires that home test kits can differentiate above and below it. Yet these home kits have a wide margin of error and they produce many false positives, the researchers say.

The new test is more clear and accurate than its counterparts. It consists of a vial that holds paint thinner and a sprinkling of certain salts that, when combined with the right concentration of lead, form a gel...

To direct-write the logo of the Department of Energy’s Oak Ridge National Laboratory, scientists started with a gray-scale image. They used the electron beam of an aberration-corrected scanning transmission electron microscope to induce palladium from a solution to deposit as nanocrystals. Image credit: Oak Ridge National Laboratory, U.S. Dept. of Energy

A scanning transmission electron microscope (STEM) has been harnessed for the first time to directly write tiny patterns in metallic “ink,” forming features in liquid that are finer than half the width of a human hair. The automated process is controlled by weaving a STEM instrument’s electron beam through a liquid-filled cell to spur deposition of metal onto a silicon microchip...

Aluminium plates which have only been sandblasted (in the background of the picture) cannot be glued successfully. The two glued plates separate again at the interface between glue and metal – this can be seen by the fact that there is no white glue residue visible on one of the two plates. The aluminium plates in the foreground of the picture were treated with the etching process “nanoscale-sculpturing” before being glued. These plates could also be separated. But the white glue particles left on both plates demonstrate that the bond between metal and glue is not broken, but rather the glue itself. Credit: Photo/Copyright: Julia Siekmann / Kiel University

Through this “nanoscale-sculpturing” process, metals such as aluminium, titanium, or zinc can permanently be joined with nearly a...

A bubble-wrapped, sponge-like device that soaks up natural sunlight and heats water to boiling temperatures, generating steam through its pores. Credit: George Ni at MIT

The solar thermal energy conversion system can easily generate steam from sunlight. It can help make technologies that rely on steam, like seawater desalination, wastewater treatment, residential water heating, medical tool sterilization and power generation, more efficient and affordable. The new device floats on water, converting 20% of incoming solar energy into steam at 100 degrees Celsius without expensive optical concentration devices and is made of cheap, commercially available materials, including bubble wrap and a polystyrene (plastic) foam.

“The system we have developed enables us to generate steam with solar ene...