BATS CHANGE EAR SHAPE AND RESHAPE THEIR SPATIAL HEARING

LC13795

- Certain bats can deform the shapes of their ears in a way that changes the animal's ultrasonic hearing spotlight. Within just one tenth of a second, these bats are able to change the configurations of their outer ear shapes from one extreme to another. As a result of these shape changes, the shape of the ultrasonic spotlight also undergoes a qualitative change. Using a combination of methods that included high-speed stereo vision and high-resolution tomography, researchers have now been able to reconstruct the three-dimensional geometries of the outer ears from live horseshoe bats as they deform on these short time scales. Using computer analysis of the deforming shapes, the researchers found ultrasonic hearing spotlights associated with the different ear configurations that could suit different hearing tasks performed by the animals. Hence, the ear deformation in horsehoe bats could be a substrate for adapting the spatial hearing of the animals on a very short time scale.

World’s fastest maze solver

LC13533E

- The authors of a recently accepted PRE paper demonstrate that a network of memristors (resistors with memory) solves the maze problem much faster than any existing supercomputer. Such an extraordinary advance in computation power is due to a massively-parallel network dynamics in which all network components are simultaneously involved in the calculation. This type of parallelism could be dubbed as “analog parallelism” which is different from that used in conventional supercomputer. It is anticipated that massively-parallel memristive processors will provide an efficient solution of many other optimization problems.

Hot electron ‘coolness’ through tunable energy transfer in nanowires

LC13992

- Harnessing and transfer of excess energy of electrons generated by light via rapid transfer of electrons across semiconductor interfaces is key to developing more efficient solar cells. In addition, hot-electron transfer is one process involved in obtaining a region of negative electrical resistance, a non-linear feature that is important in many advanced electronic devices. Researchers now report highly tunable and fast photo-excited hot electron transfer across the cylindrical interface of a co-axial core-shell semiconductor nanowire hetero-structure. The onset of the negative resistance region is shown to be highly tunable by one of three different modes, owing to the reduced dimensionality of a nanowire. Until now, the onset of negative resistance has been fixed by the selection of materials, thus requiring a network of integrated circuit components to produce tunable components important for computing, signal processing and communications. This nano-scaled multiply-tunable optically-addressed device element opens possibilities for gaining new insight into hot electron transfer processes for solar energy conversion, and for constructing complex electronic circuits using far fewer, simpler and much smaller components with the potential for requiring much less energy to operate.