Plants like the Jewelweed (Impatiens capensis; or commonly, spotted touch-me-not) use stress ingeniously for the ballistic dispersal of their seeds. The plant stores energy in its seed pods in the form of inbuilt stresses by controlling tissue hydration. When gently touched, these pods explode and curl up to launch their seeds. Using a similar concept, S. Sundaram and coworkers demonstrate the use of 3D-printing to fabricate flat electronic composites with residual stress in specific regions. Credit: Massachusetts Institute of Technology

Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and colleagues report a printable structure that begins to fold itself up as soon as it’s peeled off the printing platform...

In the long-range backscatter system developed by UW researchers, this sensor allows devices that run on extremely low power for the first time to communicate over long distances.. Credit: Dennis Wise/University of Washington

University of Washington researchers have demonstrated for the first time that devices that run on almost zero power can transmit data across distances of up to 2.8 km—breaking a long-held barrier and potentially enabling a vast array of interconnected devices. Eg, flexible electronics. But today’s flexible electronics and other sensors that can’t employ bulky batteries and need to operate with very low power typically can’t communicate with other devices more than a few feet or meters away...

AR Scorpii

Astronomers studying the unique binary star system AR Scorpii have discovered the brightness of the system has changed over the past decade. The new evidence lends support to an existing theory of how the unusual star emits energy. AR Scorpii consists of a rapidly spinning, magnetized white dwarf star that mysteriously interacts with its companion star. The system was recently found to more than double in brightness on timescales of minutes and hours, but research recently published in The Astrophysical Journal Letters found variability on a timescale of decades.

Researchers at the University of Notre Dame analyzed data on the unique system from the Kepler Space Telescope’s K2 mission taken in 2014 before the star was known to be unusual...