Category Chemistry/Nanotechnology

3-dimensional microstructures can be written using a laser, erased, and rewritten. Credit: KIT

3D printing by direct laser writing produces micrometer-sized structures with precisely defined properties. Researchers of Karlsruhe Institute of Technology (KIT) have now developed a method to erase the ink used for 3D printing. In this way, the small structures of up to 100 nm in size can be erased and rewritten repeatedly. This development opens up many new applications of 3D fabrication in biology or materials sciences, for instance.

Direct laser writing means that a computer-controlled, focused laser beam generates the structure in a photoresist similar to a pen...

(a) Crystal structure of H+ conductive coordination polymer and doped pyranine molecule, which releases/captures H+ by light irradiation. (b) Observed H+ conductivity switching property by on/off light irradiation. Credit: Image courtesy of Institute for Integrated Cell-Material Sciences at Kyoto University

Researchers at iCeMS, Japan have demonstrated on/off switching behaviour in a coordination polymer crystal. Coordination polymer crystals are inorganic and organic hybrid materials. They are known for their structural and functional diversity and their ability to conduct protons. Proton conduction is a form of electrical conduction in which hydrogen ions (H+) carry the charge instead of electrons...

Takuro Iwata, Takashi Katagiri, Yuji Matsuura. Real-Time Analysis of Isoprene in Breath by Using Ultraviolet-Absorption Spectroscopy with a Hollow Optical Fiber Gas Cell. Sensors, 2016; 16 (12): 2058 DOI: 10.3390/s16122058

Affordable gas sensor setup developed by Tohoku University team monitors trace levels of health-indicating chemicals, paving the way for future non-invasive studies. Using hollow-core optical fibre as a sensitive gas cell, researchers in Japan have devised a relatively simple and affordable sensor for monitoring biomarkers in human breath at low concentrations. Trace amounts of gases exhaled through the nose and mouth offer clues to respiratory conditions such as asthma, as well as other easy-to-administer health screening opportunities.

Tohoku University scientists expl...

A new technique for producing self-folding three-dimensional origami structures from photo-curable liquid polymer materials created these tiny samples, held in a hand for size comparison. Credit: Rob Felt, Georgia Tech

Researchers at the Georgia Institute of Technology and Peking University have found a new use for the ubiquitous PowerPoint slide: Producing self-folding 3D origami structures from photocurable liquid polymers. The technique involves projecting a grayscale pattern of light and dark shapes onto a thin layer of liquid acrylate polymer placed in a plate or between 2 glass slides. A photoinitiator material mixed into the polymer initiates a crosslinking reaction when struck by light from an ordinary LED projector, causing a solid film to form...