News by Subject Chemistry & Physics

Tokyo, Japan - Researchers from Tokyo Metropolitan University have developed a new technology which allows non-contact manipulation of small objects using sound waves. They used a hemispherical array of ultrasound transducers to generate a 3D acoustic fields which stably trapped and lifted a small polystyrene ball from a reflective surface. Although their technique employs a method similar to laser trapping in biology, adaptable to a wider range of particle sizes and materials.

As reported in Advanced Photonics, researchers from Shanghai University and Fudan University developed a general framework and metadevices for achieving dynamic control of THz wavefronts. Instead of locally controlling the individual meta-atoms in a THz metasurface (e.g., via PIN diode, varactor, etc.), they vary the polarization of a light beam with rotating multilayer cascaded metasurfaces.

In research published in the journal Optica, University of California, Irvine researchers describe a new type of camera technology that, when aimed at an object, can rapidly retrieve 3D images, displaying its chemical content down to the micrometer scale.

Toyohashi University of Technology used a material with a unique periodical structure as a host material to synthesize new Mn4+-activated phosphors that exhibit red light emissions at 685 nm when excited at 493 nm. Because the valence of the Mn ions in the material changes from Mn4+ to Mn3+ according to the sintering temperature, composition, and crystal structure, there is a difference in the photoluminescence intensity of the phosphors.

A team of researchers has developed a simplified method to perform the necessary calibration of optical tweezers. Shortening the measurement time helps to reduce the risk of damage to biological samples due to light-induced heating.

Neuromodulation at high spatial resolution is crucial for advancing understanding of brain circuits and treatment of neurological diseases. Here, a tapered fiber optoacoustic emitter (TFOE) is developed for stimulation of single neurons and subcellular structures. The TFOE enabled integration with patch clamp recording and unveiled cell-type-specific response of excitatory and inhibitory neurons to photoacoustic stimulation. TFOE provides a non-genetic single-cell and sub-cellular modulation platform, which could shed new insights into the mechanism of ultrasound neurostimulation.

Using long wavelength near-infrared light, scientists at UC Davis developed a label-free microscopy approach that achieves a unique combination of deep, high resolution, and minimally invasive brain imaging. The technique images neurons and axonal myelination across the mouse neocortex and some sub-cortical regions, through the thinned skull. Now studies of brain disease can be conducted deep in the mouse brain through a minimally invasive and simple surgical preparation.

This is the first ever capture of the ultrafast motions of a high intensity laser produced plasma on a solid surface, simultaneously at different spatial locations. It achieves an experimental leap in Doppler spectrometry and is important for tracking the flow of heat and energy along the surface and watching the growth of plasma instabilities, all very important for understanding laser plasma science and pushing forward applications of high intensity, femtosecond laser driven laser plasmas.