Mechanical & Fluid Systems

Mechanical Actuators Bend as They “Breathe”

The equipment used for testing the new materials. (Credit: MIT)

Extreme temperatures can severely strain a mechanical component because its material may have trouble enduring the heat without degrading. To address the problem, researchers at MIT developed a new material that expands and contracts as it lets oxygen in and out. The result is a new way to make actuators that could be used in extremely hot environments.

Posted in: News, Materials, Mechanical Components, Motion Control

Magnetic Fields Enable New Soft Robots

Researchers from North Carolina State University have a found a new way to control robots. The team used magnetic fields to remotely manipulate microparticle chains embedded in soft robotic devices.

Posted in: News, Joining & Assembly, Drug Delivery, Automation, Robotics

'Snap' Design Mimics Venus Flytrap

A team led by physicist Christian Santangelo at the University of Massachusetts Amherst uses curved creases to give thin shells a fast, programmable snapping motion. The technique – inspired by the natural "snapping systems" like Venus flytrap leaves and hummingbird beaks – avoids the need for complicated materials and fabrication methods when creating structures with fast dynamics.

Posted in: News, Materials, Joining & Assembly, Mechanical Components

NASA Advances Next-Generation 3D-Imaging Lidar

Building, fixing, and refueling space-based assets or rendezvousing with a comet or asteroid will require a robotic vehicle and a super-precise, high-resolution 3D imaging lidar that will generate real-time images needed to guide the vehicle to a target traveling at thousands of miles per hour. A team at NASA’s Goddard Space Flight Center is developing a next-generation 3D scanning lidar — dubbed the Goddard Reconfiguable Solid-state Scanning Lidar (GRSSLi) — that could provide the imagery needed to execute these orbital dances.

GRSSLi is a small, low-cost, low-weight platform capable of centimeter-level resolution over a range of distances, from meters to kilometers. Equipped with a low-power, eye-safe laser; a MEMS scanner; and a single photodetector, GRSSLi will "paint" a scene with the scanning laser, and its detector will sense the reflected light to create a high-resolution 3D image at kilometer distances.

A non-scanning version of GRSSLi would be ideal for close approaches to asteroids. It would employ a flash lidar, which doesn’t paint a scene with a mechanical scanner, but rather illuminates the target with a single pulse of laser light — much like a camera flash.


Posted in: News, Aerospace, Electronics & Computers, Imaging, MEMs, Lasers & Laser Systems, Photonics, Automation, Robotics

NASA Tests Revolutionary Shape-Changing Aircraft Flap

NASA's green aviation project is one step closer to developing technology that could make future airliners quieter and more fuel‑efficient with the successful flight test of a wing surface that can change shape in flight. Researchers replaced an airplane’s conventional aluminum flaps with advanced, shape‑changing assemblies that form seamless bendable and twistable surfaces. Flight testing will determine whether flexible trailing‑edge wing flaps are a viable approach to improve aerodynamic efficiency and reduce noise generated during takeoffs and landings.

Posted in: News, Aerospace, Aviation, Mechanical Components

Pulley Mechanism Improves Hand Function After Surgery

Engineers at Oregon State University have developed and successfully demonstrated a simple pulley mechanism to improve hand function after surgery. The device is one of the first instruments ever created that could improve the transmission of mechanical forces and movement while implanted inside the body.

Posted in: News, Mechanical Components, Medical, Rehabilitation & Physical Therapy, Motion Control

Untethered Soft Robot Walks Through Flames

Developers from Harvard’s School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering have produced the first untethered soft robot — a quadruped that can stand up and walk away from its designers.The researchers were able to scale up earlier soft-robot designs, enabling a single robot to carry on its back all the equipment it needs to operate — micro-compressors, control systems, and batteries.Compared with earlier soft robots, which were typically no larger than a steno pad, the system is huge, measuring more than a half-meter in length and capable of carrying as much as 7½ pounds on its back.Giving the untethered robot the strength needed to carry mechanical components meant air pressures as high as 16 pounds per square inch, more than double the seven psi used by many earlier robot designs. To deal with the increased pressure, the robot had to be made of tougher stuff.The material settled on was a “composite” silicone rubber made from stiff rubber impregnated with hollow glass microspheres to reduce the robot’s weight. The robot’s bottom was made from Kevlar fabric to ensure it was tough and lightweight. The result was a robot that can stand up to a host of extreme conditions.SourceAlso: Learn about a Field-Reconfigurable Manipulator for Rovers.

Posted in: News, Composites, Materials, Mechanical Components, Motion Control, Motors & Drives, Automation, Robotics

Researchers Develop Solar Technologies, Origami-Style

As a high school student at a study program in Japan, Brian Trease would fold wrappers from fast-food cheeseburgers into cranes. He loved discovering different origami techniques in library books.Today, Trease, a mechanical engineer at NASA’s Jet Propulsion Laboratory in Pasadena, California, thinks about how the principles of origami could be used for space-bound devices.Researchers say origami could be useful one day in utilizing space solar power for Earth-based purposes. Imagine an orbiting power plant that wirelessly beams power down to Earth using microwaves. Sending the solar arrays up to space would be easy, Trease said, because they could all be folded and packed into a single rocket launch, with "no astronaut assembly required."Panels used in space missions already incorporate simple folds, collapsing like a fan or an accordion. But Trease and colleagues are interested in using more intricate folds that simplify the overall mechanical structure and make for easier deployment.Last year, Zirbel and Trease collaborated with origami expert Robert Lang and BYU professor Larry Howell to develop a solar array that folds up to be 8.9 feet (2.7 meters) in diameter. Unfold it, and you’ve got a structure 82 feet (25 meters) across.SourceAlso: Learn about Origami-Inspired Folding of Thick, Rigid Panels.

Posted in: News, Aerospace, Energy, Energy Harvesting, Renewable Energy, Solar Power, Mechanical Components, Antennas, RF & Microwave Electronics

Airbags Take the Weight in Load Tests of Aircraft

NASA Armstrong Flight Research Center’s Flight Loads Laboratory completed structural evaluations on a modified Gulfstream G-III aircraft that will serve as a test bed for the Adaptive Compliant Trailing Edge (ACTE) project. The loads tests assisted engineers in predicting the levels of structural stress the airplane will likely experience during ACTE research flights. And for the first time, some unusual hardware aided the process: the aircraft was supported by three large inflatable airbags during the tests.

Posted in: News, Aerospace, Aviation, Mechanical Components, Test & Measurement

'Active' Surfaces Control How Particles Move

Researchers at MIT and in Saudi Arabia have developed a new way of making surfaces that can actively control how fluids or particles move across them. The work might enable new kinds of biomedical or microfluidic devices, or solar panels that could automatically clean themselves of dust and grit.The system makes use of a microtextured surface, with bumps or ridges just a few micrometers across, that is then impregnated with a fluid that can be manipulated — for example, an oil infused with tiny magnetic particles, or ferrofluid, which can be pushed and pulled by applying a magnetic field to the surface. When droplets of water or tiny particles are placed on the surface, a thin coating of the fluid covers them, forming a magnetic cloak.The thin magnetized cloak can then actually pull the droplet or particle along as the layer itself is drawn magnetically across the surface. Tiny ferromagnetic particles, approximately 10 nanometers in diameter, in the ferrofluid could allow precision control when it’s needed — such as in a microfluidic device used to test biological or chemical samples by mixing them with a variety of reagents. Unlike the fixed channels of conventional microfluidics, such surfaces could have “virtual” channels that could be reconfigured at will.The new approach could be useful for a range of applications: For example, solar panels and the mirrors used in solar-concentrating systems can quickly lose a significant percentage of their efficiency when dust, moisture, or other materials accumulate on their surfaces. But if coated with such an active surface material, a brief magnetic pulse could be used to sweep the material away.Source

Also: Read more Materials tech briefs.

Posted in: News, Energy, Renewable Energy, Solar Power, Fluid Handling, Drug Delivery, Medical, Motion Control

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