Tag Archives: Michigan Technological University (MTU)

Watching a nanosized space rocket under a microscope

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That is a silent video depicting the research. For anyone who may be puzzled, there’s an Aug. 8, 2016 news item on Nanowerk featuring the research announcement from Michigan Technological University (Note: A link has been removed),

Researchers at the University of Maryland and Michigan Technological University have operated a tiny proposed satellite ion rocket under a microscope to see how it works (Nanotechnology, “Radiation-induced solidification of ionic liquid under extreme electric field”).

The rocket, called an electrospray thruster, is a drop of molten salt. When electricity is applied, it creates a field on the tip of the droplet, until ions begin streaming off the end. The force created by the rocket is less than the weight of a human hair, but in the vacuum of space it is enough to push a small object forward with a constant acceleration. Many of these tiny thrusters packed together could propel a spacecraft over great distances, maybe even to the nearest exoplanet, and they are particularly useful for Earth-orbiting nanosatellites, which can be as small as a shoe box. These thrusters are currently being tested on the European Space Agency’s LISA Pathfinder, which hopes to poise objects in space so precisely that they would only be disturbed by gravitational waves.

An Aug, 8, 2016 Michigan Technological University news release on EurekAlert, which originated the news item, explains further,

…

these droplet engines have a problem: sometimes they form needle-like spikes that disrupt the way the thruster works – they get in the way of the ions flowing outward and turn the liquid to a gel. Lyon B. King and Kurt Terhune, mechanical engineers at Michigan Tech, wanted to find out how this actually happens.

“The challenge is making measurements of features as small as a few molecules in the presence of a strong electric field, which is why we turned to John Cumings at the University of Maryland,” King says, explaining Cumings is known for his work with challenging materials and that they needed to look for a needle in a haystack. “Getting a close look at these droplets is like looking through a straw to find a penny somewhere on the floor of a room–and if that penny moves out of view, like the tip of the molten salt needles do–then you have to start searching for it all over again.”

At the Advanced Imaging and Microscopy Lab at the University of Maryland, Cumings put the tiny thruster in a transmission electron microscope – an advanced scope that can see things down to millionths of a meter. They watched as the droplet elongated and sharpened to a point, and then started emitting ions. Then the tree-like defects began to appear.

The researchers say that figuring out why these branched structures grow could help prevent them from forming. The problem occurs when high-energy electrons, like those used in the microscope’s imaging beam, impact the fluid causing damage to the molecules that they strike. This damages the molten salt’s molecular structure, so it thickens into a gel and no longer flows properly.

“We were able to watch the dendritic structures accumulate in real time,” says Kurt Terhune, a mechanical engineering graduate student and the study’s lead author. “The specific mechanism still needs to be investigated, but this could have importance for spacecraft in high-radiation environments.”

He adds that the microscope’s electron beam is more powerful than natural settings, but the gelling effect could affect the lifetime of electrospray thrusters in low-Earth and geosynchronous orbit.

Here’s a link to and a citation for the paper,

Radiation-induced solidification of ionic liquid under extreme electric field by Kurt J Terhune, Lyon B King, Kai He, and John Cumings. Nanotechnology, Volume 27, Number 37 DOI: http://dx.doi.org/10.1088/0957-4484/27/37/375701 Published 3 August 2016

© 2016 IOP Publishing Ltd

This paper is behind a paywall.

You gotta shake, shake, shake those nanomaterials out of the water

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A team at Michigan Technological University (Michigan Tech) has developed a simple technique for clearing nanoparticles from water according to a Dec. 10, 2015 news item on Nanotechnology Now,

Nano implies small—and that’s great for use in medical devices, beauty products and smartphones—but it’s also a problem. The tiny nanoparticles, nanowires, nanotubes and other nanomaterials that make up our technology eventually find their way into water. The Environmental Protection Agency says more 1,300 commercial products use some kind of nanomaterial. And we just don’t know the full impact on health and the environment.

A Dec. 10, 2015 Michigan Tech news release, which originated the news item, describes the concept and the research in more detail,

“Look at plastic,” says Yoke Khin Yap, a professor of physics at Michigan Technological University. “These materials changed the world over the past decades—but can we clean up all the plastic in the ocean? We struggle to clean up meter-scale plastics, so what happens when we need to clean on the nano-scale?”

…

The method sounds like a salad dressing recipe: take water, sprinkle in nanomaterials, add oil and shake.

Water and oil don’t mix, of course, but shaking them together is what makes salad dressing so great. Only instead of emulsifying and capturing bits of shitake or basil in tiny olive oil bubbles, this mixture grabs nanomaterials.

Dongyan Zhang, a research professor of physics at Michigan Tech, led the experiments, which covered tests on carbon nanotubes, graphene, boron nitride nanotubes, boron nitride nanosheets and zinc oxide nanowires. Those are used in everything from carbon fiber golf clubs to sunscreen.

“These materials are very, very tiny, and that means if you try to remove them and clean them out of contaminated water, that it’s quite difficult,” Zhang says, adding that techniques like filter paper or meshes often don’t work.

What makes shaking work is the shape of one- and two-dimensional nanomaterials. As the oil and water separate after some rigorous shaking, the wires, tubes and sheets settle at the bottom of the oil, just above the water. The oils trap them. However, zero-dimensional nanomaterials, such as nanospheres do not get trapped.

The researchers, according to the news release, are attempting to anticipate the potential contamination of our water supply by nanomaterials and provide a solution before it happens,

We don’t have to wait until the final vote is in on whether nanomaterials have a positive or negative impact on people’s health and environmental health. With the simplicity of this technique, and how prolific nanomaterials are becoming, removing nanomaterials makes sense. Also, finding ways to effectively remove nanomaterials sooner rather than later could improve the technology’s market potential.

“Ideally for a new technology to be successfully implemented, it needs to be shown that the technology does not cause adverse effects to the environment,” Yap, Zhang and their co-authors write. “Therefore, unless the potential risks of introducing nanomaterials into the environment are properly addressed, it will hinder the industrialization of products incorporating nanotechnology.”

Purifying water and greening nanotechnology could be as simple as shaking a vial of water and oil.

Here’s a video about the research supplied by Michigan Tech,

Here’s a link to and a citation for the paper,

A Simple and Universal Technique To Extract One- and Two-Dimensional Nanomaterials from Contaminated Water by Bishnu Tiwari, Dongyan Zhang, Dustin Winslow, Chee Huei Lee, Boyi Hao, and Yoke Khin Yap. ACS Appl. Mater. Interfaces, 2015, 7 (47), pp 26108–26116 DOI: 10.1021/acsami.5b07542 Publication Date (Web): November 9, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

3D printing and the environment (a panel discussion at the Woodrow Wilson International Center for Scholars), and new developments with metal 3D printing

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I have combined two 3D printing items here. The first is an announcement from the Woodrow Wilson International Center for Scholars about an upcoming panel discussion (from the Nov. 25, 2013 announcement),

The Environmental Impacts of 3D Printing

3D printing allows for cheaper and quicker production of complex and novel items. The technology has been used by industry to build prototypes and specialized parts since the 1980s, but interest in desktop applications of the technology has increased in recent years as prices for the machines have dropped.

Proponents of the technology often cite the environmental benefits of 3D printing, though fundamental questions remain: What technologies are involved in 3D printing? How efficient are these technologies in the use of materials and energy? Does the design of printed objects reduce end-of-life options? Does more localized production reduce the carbon footprint? Will simplicity and ubiquity cause us to overprint things, just as we do with paper?

Robert Olson explored some of these questions in his article “3D Printing: A Boon or a Bane?” in the November/December 2013 issue of the Environmental Forum. The article discusses the enormous potential of 3D printing and examines the paucity of research on the environmental impacts of the technology.

Join us at the Wilson Center on Dec. 13 for an event looking at the growth of additive manufacturing and the potential environmental implications of the technology.

When: Dec. 13, 2013 from 9 a.m. – 11 a.m. EST

Who:

  • Robert Olson, Senior Fellow, Institute for Alternative Futures
  • David Rejeski, Director, Science and Technology Innovation Program, Wilson Center
  • John Pendergrass, Senior Attorney & Director of the State Center, Environmental Law Institute

There is more information on the Event page.

While this panel discussion is likely to be focused on polymer 3D printing, there are other developments in the 3D printing world as per a Nov. 26, 2013 Michigan Technological University (MTU) news release (also on EurekAlert, Dec. 2, 2013),

OK, so maybe you aren’t interested in making your own toys, cellphone cases, or glow-in-the-dark Christmas decorations. How about a brake drum?

Until now, 3D printing has been a polymer affair, with most people in the maker community using the machines to make all manner of plastic consumer goods, from tent stakes to chess sets. A new low-cost 3D printer developed by Michigan Technological University’s Joshua Pearce and his team could add hammers to that list. The detailed plans, software and firmware are all freely available and open-source, meaning anyone can use them to make their own metal 3D printer.

This open access technology is being made accessible to the maker community, preferably to the highly skilled and experienced members, (from the news release),

Pearce is the first to admit that his new printer is a work in progress. So far, the products he and his team have produced are no more intricate than a sprocket. But that’s because the technology is so raw. “Similar to the incredible churn in innovation witnessed with open-sourcing of the first RepRap plastic 3D printers, I anticipate rapid progress when the maker community gets their hands on it,” says Pearce, an associate professor of materials science and engineering/electrical and computer engineering. “Within a month, somebody will make one that’s better than ours, I guarantee it.”

Using under $1,500 worth of materials, including a small commercial MIG welder and an open-source microcontroller, Pearce’s team built a 3D metal printer than can lay down thin layers of steel to form complex geometric objects. Commercial metal printers are available, but they cost over half a million dollars.

His make-it-yourself metal printer is less expensive than off-the-shelf commercial plastic 3D printers and is affordable enough for home use, he said. However, because of safety concerns, Pearce suggests that for now it would be better off in the hands of a shop, garage or skilled DIYer, since it requires more safety gear and fire protection equipment than the typical plastic 3D printer.

While metal 3D printing opens new vistas, it also raises anew the specter of homemade firearms. Some people have already made guns with both commercial metal and plastic 3D printers, with mixed results. While Pearce admits to some sleepless nights as they developed the metal printer, he also believes that the good to come from all types of distributed manufacturing with 3D printing will far outweigh the dangers.

In previous work, his group has already shown that making products at home with a 3D printer is cheaper for the average American and that printing goods at home is greener than buying commercial goods.

In particular, expanded 3D printing would benefit people in the developing world, who have limited access to manufactured goods, and researchers, who can radically cut costs of scientific equipment to further their science, Pearce said. “Small and medium-sized enterprises would be able to build parts and equipment quickly and easily using downloadable, free and open-source designs, which could revolutionize the economy for the benefit of the many.”

“I really don’t know if we are mature enough to handle it,” he added cautiously, “but I think that with open-source approach, we are within reach of a Star Trek-like, post-scarcity society, in which ‘replicators’ can create a vast array of objects on demand, resulting in wealth for everyone at very little cost. Pretty soon, we’ll be able to make almost anything.”

There is a paper and here’s a citation,of sorts,

“A Low-Cost, Open-Source Metal 3-D Printer,” to be published Nov. 25 in IEEE Access (DOI: 10.1109/ACCESS.2013.2293018)

Unfortunately I’ve not been able to locate this paper on IEEE {Institute of Electrical and Electronics Engineers]  Access.