#ingenious engineering

Sound exerts a small acoustic force and by turning up the volume of ultrasonic waves, too high pitched for humans to hear, scientists create a sound field strong enough to move small objects. Researchers have enabled the efficient generation of sound fields complex enough to trap multiple objects at the target locations.

To demonstrate the accuracy of their system, the scientists attached two millimetric polystyrene spheres to a piece of thread and used the acoustic tweezers to "sew" the thread into a piece of fabric. The system can also simultaneously control the 3D movement of up to 25 of these spheres in air.

Find out more:

http://www.bristol.ac.uk/news/2018/december/sound-waves.html

The phononic devices include parts that vibrate extremely fast, moving back and forth up to tens of millions of times per second. The team developed these devices by creating silicon nitride drums that are just 90 nanometers thick. (A human hair is about a thousand times thicker.) The drums are arranged into grids, with different grid patterns having different properties.

Daraio, along with former Caltech postdoctoral scholar Jinwoong Cha showed that arrays of these drums can act as tunable filters for signals of different frequencies. They also showed that the devices can act like one-way valves for high-frequency waves. The ability to transmit waves in only one direction helps keep the signal stronger by reducing interference.

Find out more:

http://www.caltech.edu/news/microscopic-devices-control-vibrations-could-allow-smaller-mobile-devices-84641

The spacecraft executed a maneuver that transitioned it from flying toward Bennu to operating around the asteroid.  Now, at about 11.8 miles (19 kilometers) from Bennu’s Sun-facing surface, OSIRIS-REx will begin a preliminary survey of the asteroid. The spacecraft will commence flyovers of Bennu’s north pole, equatorial region, and south pole, getting as close as nearly 4 miles (7 kilometers) above Bennu during each flyover.

OSIRIS-REx’s mission will help scientists investigate how planets formed and how life began, as well as improve our understanding of asteroids that could impact Earth. Asteroids are remnants of the building blocks that formed the planets and enabled life. Those like Bennu contain natural resources, such as water, organics and metals. Future space exploration and economic development may rely on asteroids for these materials.

Find out more:

https://www.nasa.gov/press-release/nasas-osiris-rex-spacecraft-arrives-at-asteroid-bennu

In order for a modern transport aircraft to safely operate at slow speeds for landing and takeoff operations, a high-lift system consisting of slotted flaps on the trailing edge of the wing is used to achieve the required lift performance. However, the slotted flaps and the associated subsystems are complex and protrude under the wing such that they increase air resistance, and consequently fuel burn, during cruise.

The NASA Advanced Air Transport Technology (AATT) Project is sponsoring the current research effort aimed at reducing the fuel burn of modern transport aircraft by replacing a conventional slotted flap with a simple-hinged flap featuring an integrated active flow control (AFC) system.

Find out more:

https://www.nasa.gov/image-feature/langley/high-lift-aerodynamic-wing-design-tested-at-nasa-langley-tunnel

SpaceBok is a quadruped robot designed by a Swiss student team from ETH Zurich and ZHAW Zurich, under the supervision of Professor Marco Hutter and PhD student Hendrik Kolvenbach, for future missions to the Moon or Mars.

Legged robots have the advantage of traversing unstructured terrain and could be used to explore areas of interest, such as craters, which rovers are unable to reach. SpaceBok is primarily built for hopping, which is not particularly useful on Earth but could allow it to reach heights of up to four metres on the Moon. This would allow for a fast and efficient way of moving forward.

Find out more:

http://www.esa.int/spaceinimages/Images/2018/11/SpaceBok_robot

Unlike turbine-powered planes, the aircraft does not depend on fossil fuels to fly. And unlike propeller-driven drones, the new design is completely silent. Instead of propellers or turbines, the light aircraft is powered by an “ionic wind” — a silent but mighty flow of ions that is produced aboard the plane, and that generates enough thrust to propel the plane over a sustained, steady flight.

MIT engineers expect that in the near-term, such ion wind propulsion systems could be used to fly less noisy drones. Further out, he envisions ion propulsion paired with more conventional combustion systems to create more fuel-efficient, hybrid passenger planes and other large aircraft.

Find out more:

http://news.mit.edu/2018/first-ionic-wind-plane-no-moving-parts-1121

The “smart stickers” are made of cellulose, which is both biocompatible and breathable. They can be used to monitor physical activity and alert a wearer about possible health risks in real time. Since  paper  degrades  fast  when  it gets  wet  and  human  skin  is  prone  to  be  covered  in  sweat,  these  stickers were  coated  with  molecules  that  repel  water,  oil,  dust  and  bacteria.  Each sticker costs about a nickel to produce and can be made using printing and manufacturing technologies similar to those used to print books at high speed.

Since  paper  degrades  fast  when  it  gets  wet  and  human  skin  is  prone  to be  covered  in  sweat,  these  stickers  were  coated  with  molecules  that  repel water,  oil,  dust  and  bacteria.  Each sticker costs about a nickel to produce and can be made using printing and manufacturing technologies similar to those used to print books at high speed.

Find out more:

https://www.purdue.edu/newsroom/releases/2018/Q4/simple-stickers-may-save-lives-of-heart-patients,-athletes-and-lower-medical-costs-for-families.html

MRI works by detecting radio waves emitted by the nuclei of hydrogen atoms in water. These signals are usually detected by a large radio antenna within an MRI scanner. For this study, the MIT team shrank the radio antenna down to just a few millimeters in size so that it could be implanted directly into the brain to receive the radio waves generated by water in the brain tissue.

When the sensor picks up an electromagnetic signal from the tissue, its tuning changes and the sensor no longer matches the frequency of the hydrogen atoms. When this happens, a weaker image arises when the sensor is scanned by an external MRI machine. The researchers demonstrated that the sensors can pick up electrical signals similar to those produced by action potentials (the electrical impulses fired by single neurons), or local field potentials (the sum of electrical currents produced by a group of neurons).

Find out more:

http://news.mit.edu/2018/monitoring-electromagnetic-signals-brain-mri-1022