Tag Archives: Northeastern University

Directed assembly—faster, better, cheaper than 3D printing

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Ahmed Bus­naina, director of the NSF (US National Science Foundation) Nanoscale Sci­ence and Engi­neering Center for High-​​rate Nanoman­u­fac­turing at North­eastern University explained current 3D printing technology and how his directed assembly method constitutes a serious upgrade in a Northeastern University Mar. 14, 2013 news release by Angela Herring,

The modern 3-​​D printer is basi­cally a spe­cial­ized ink-​​jet printer. It uses a printer head with spe­cial ink that could con­tain a polymer, par­ti­cles, or nan­otubes sus­pended in solu­tion, or really any­thing. It prints line by line, so prod­ucts requiring higher res­o­lu­tion or large areas take a very long time.

What we have devel­oped at our center is a system that’s like news­paper printing or printing money, where you have a big plate, you put ink on it, and bang: One hit, you’re done. Only here, the ink is made of very small and very sen­si­tive nanopar­ti­cles attracted to the tem­plate using elec­trophoresis, so we have to pick exact dimen­sions and materials.

We put a tem­plate with a pat­tern rep­re­sented by nanowires into a solu­tion that is sim­ilar to ink, but very dilute. Then we apply a couple of volts so that nanopar­ti­cles in the ink are drawn to the nanowires. Then we take out the tem­plate and transfer the assem­bled nanopar­ti­cles to a sur­face of either a hard or flex­ible sub­strate. That would be the first layer of a device, which takes about a minute or two. A sensor may have just a few layers, where advanced elec­tronics may have 10 layers or more.

Busnaina contrasts the speed and range of scales between the current method and his directed assembly method (from the news release),

For low-​​cost, low-​​end prod­ucts, 3-​​D printers are very good but they are slow—it can take days to print a single product. But with directed assembly, we can do low-​​cost, high-​​end prod­ucts, and we can do them very quickly. So, directed assembly will be very valu­able for high-​​value devices like sen­sors, advanced elec­tronics, energy har­vesting, or bat­teries. It might also be used for tissue engi­neering and printing bio­ma­te­rials like cells or proteins.

Directed assembly allows 3-​​D printing to be faster, cheaper, and mul­ti­scale. It can do nano, micro, and macro simul­ta­ne­ously over a large area. No 3-​​D printer can do that; this is beyond the cur­rent 3-​​D printing tech­nology. This will reduce the cost of expen­sive elec­tronics such as an iPhone for less than $10 and sensor sys­tems for a frac­tion of a dollar. These could be sen­sors for health, the envi­ron­ment, infra­struc­ture, water resources, any­thing. They will make advanced prod­ucts afford­able to people in all income classes, not just high-​​income pop­u­la­tions or countries.

What we’re trying to do is make high-​​value things, such as sen­sors, energy-​​harvesting devices, or phone dis­plays, using this tech­nology, which costs 1 per­cent of con­ven­tional man­u­fac­turing. That also means you can make all kinds of devices by design, printing things exactly to specifications—even down to the nanoscale (one thou­sand times smaller than a human hair).

For example, we devel­oped an energy-​​harvesting device that can use any heat source—even body heat—to charge a sensor or a phone. An antenna absorbs heat and con­verts it to cur­rent. We print it using carbon nan­otubes for the ink. This kind of device would not be pos­sible with tra­di­tional 3-​​D printing—it just can’t go that small.

Exciting stuff and you can read more about it at the Northeastern University website or where I first found the item at phys.org.

 

S.NET 2013 call for proposals

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The fifth annual meeting of the Society for the Study of Nanoscience and Emerging Technologies (S.NET) will be taking place Oct. 27 – 30, 2013 at Northeastern University in Boston, Massachusetts. The call for proposals was sent out yesterday, Mar. 5, 2013,

Proposals are now being solicited for the 2013 annual meeting of the Society for the Study of Nanoscience and Emerging Technologies (S.NET), to be held at Northeastern University, Boston, October 27-30. At this point we are open to all suggestions, ranging from standard papers, presentation, and posters to ideas for concurrent workshops, plenary sessions, and special roundtables.
Our theme for the 2013 meeting is Innovation, Responsibility, and Sustainable Development. Boston is a literal hub for innovation, and the theme fits in well with the region’s traditions and current strengths in a wide range of technologies. Moreover, as we have stressed from its origins, the Society seeks to advance critical reflection from various perspectives on developments in a broad range of new and emerging fields, including, but not limited to, nanoscale science and engineering, biotechnology, synthetic biology, cognitive science and geo-engineering.
Proposals can be submitted until May 1 via the S.NET Submission Portal. The Program Committee will assess all proposals and respond by June 15 [2013].

You can read the full call announcement here in a Mar. 2, 2013 posting on the Nanotechnology and Society Research Group (NSRG) blog. The NSRG is located at Northeastern University.

Natural and engineered nanoparticles in an Orion magazine podcast & in a NanoBosc machinima piece

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The Jan. 16, 2013 Orion magazine podcast discussion (more about that later) regarding safety and engineered and natural nanoparticles arose from an article (worth reading) by Heather Millar in the magazine’s January/February 2013 issue, Pandora’s Boxes.

For anyone familiar with the term ‘Pandora’s box’, Millar’s and the magazine’s bias is made clear immediately, nanoparticles are small and threatening. From the Pandora’s box Wikipedia essay,

Today, the phrase “to open Pandora’s box” means to perform an action that may seem small or innocuous, but that turns out to have severe and far-reaching consequences. [emphases mine]

Millar’s article is well written and offers some excellent explanations. For example, there’s this from Pandora’s Boxes,

So chemistry and physics work differently if you’re a nanoparticle. You’re not as small as an atom or a molecule, but you’re also not even as big as a cell, so you’re definitely not of the macro world either. You exist in an undiscovered country somewhere between the molecular and the macroscopic. Here, the laws of the very small (quantum mechanics) merge quirkily with the laws of the very large (classical physics). Some say nanomaterials bring a third dimension to chemistry’s periodic table, because at the nano scale, long-established rules and groupings don’t necessarily hold up.

Then, she has some dodgier material,

Yet size seems to be a double-edged sword in the nanoverse. Because nanoparticles are so small, they can slip past the body’s various barriers: skin, the blood-brain barrier, the lining of the gut and airways. Once inside, these tiny particles can bind to many things. They seem to build up over time, especially in the brain. Some cause inflammation and cell damage. Preliminary research shows this can harm the organs of lab animals, though the results of some of these studies are a matter of debate.

Some published research has shown that inhaled nanoparticles actually become more toxic as they get smaller. Nano–titanium dioxide, one of the most commonly used nanoparticles (Pop-Tarts, sunblock), has been shown to damage DNA in animals and prematurely corrode metals. Carbon nanotubes seem to penetrate lungs even more deeply than asbestos. [emphases mine]

I think it’s worth ‘unpacking’ these two paragraphs, so here goes.  Slipping past the body’s barriers is a lot more difficult than Millar suggests in the first paragraph. My July 4, 2012 posting on breakthough research  where they penetrated the skin barrier includes this comment from me,

After all the concerns  about nanosunscreens and nanoparticles penetrating the skin raised by civil society groups, the Friends of the Earth in particular, it’s interesting to note that doctors and scientists consider penetration of the skin barrier to be extremely difficult. Of course, they seem to have solved [as of July 2012] that problem which means the chorus of concerns may rise to new heights.

I had a followup in my Oct.3, 2012 posting titled, Can nanoparticles pass through the skin or not?, suggesting there’s still a lot of confusion about this topic even within the scientific community.

Moving on to the other ‘breaches’. As I recall, there was a recent  (Autumn 2012?) nanomedicine research announcement that the blood-brain barrier was breached by nanoparticles. I haven’t yet encountered any mention of breaching the gut and I mention lungs in my next paragraph where I discuss carbon nanotubes.

As for that second paragraph, it’s an example of scaremongering. ‘Inhaled nanoparticles become more toxic as their size decreases’—ok. Why mention nano-titanium oxide in pop tarts and sunblocks, which are not inhaled, in the followup sentence? As for the reference to DNA damage and corroded metals further on, this is straight out of the Friends of the Earth literature which often cites research in a misleading fashion including those two pieces.  There is research supporting part of Millar’s statement about carbon nanotubes—provided they are long and multiwalled. In fact, as they get shorter, the resemblance to asbestos fibers in the lungs or elsewhere seems to disappear as per my Aug 22, 2012 posting and my Jan. 16, 2013 posting.

You don’t need to read the article before listening to the fascinating Jan. 16, 2013 Orion magazine podcast with Millar (reading portions of her article) and expert guests, Mark Wiesner from Duke University and director of their Center for Environmental Implications of Nano Technology (CEINT was first mentioned in my April 15, 2011 posting), Ronald Sandler from Northeastern University and author of Nanotechnology: The Social And Ethical Issues, and Jaydee Hanson, policy director for the International Center for Technology Assessment.

The discussion between Wiesner, Sandler, and Hanson about engineered and natural nanoparticles is why I’ve called the podcast fascinating. Hearing these experts ‘fence’ with each other highlights the complexities and subtleties inherent in discussions about emerging technologies (nano or other) and risk. Millar did not participate in that aspect of the conversation and I imagine that’s due to the fact that she has only been researching this area for six months while the other speakers all have several years worth experience individually and, I suspect, may have debated each other previously.

At the risk of enthusing too much about naturally occurring nanoparticles, I’m mentioning, again (my Feb. 1, 2013 posting), the recently published book by Nanowiki, Nanoparticles Before Nanotechnology, in the context of the stunning visual images used to illustrate the book. I commented previously about them and Victor Puntes of the Inorganic Nanoparticles Group at the Catalan Institute of Nanotechnology (ICN) and one of the creators of this imagery, kindly directed me to a machinima piece (derived from the NanoBosc Second Life community) which is the source for the imagery. Here it is,

NanoBosc from Per4mance MetaLES ..O.. on Vimeo.

Happy Weekend!

Bacterial nanobots build a pyramid; solar cell breakthrough in Quebec; global nano regulatory framework conference at Northeastern University; Robert Fulford talks about the poetry of nanotechnology

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Just when I was thinking that the Canadian nanotechnology scene was slowing down there’s this: A research team at the École Polytechnique de Montréal (Québec) has announced that they’ve trained bacteria to build structures shaped like pyramids. From the news item on Nanowerk,

Faster than lion tamers… More powerful than snake charmers… Make way for the bacteria trainers! Professor Sylvain Martel and his team at the École Polytechnique de Montréal NanoRobotics Laboratory have achieved a new world first: “training” living bacteria to build a nanopyramid.

These miniature construction workers are magnetotactic bacteria (MTB): they have their own internal compasses, allowing them to be pulled by magnetic fields. MTB possess flagella bundles enabling each individual to generate a thrust force of approximately 4 picoNewtons. Professor Martel’s team has succeeded in directing the motion of a group of such bacteria using computer-controlled magnetic fields. In an experiment conducted by Polytechnique researchers, the bacteria transported several epoxy nanobricks and assembled them into a step-pyramid structure, completing the task in just 15 minutes. The researchers have also managed to pilot a group of bacteria through the bloodstream of a rat using the same control apparatus.

Nanowerk also features a video of the magnetotactic bacteria at work.

Solar cell breakthrough?

More Canadian nano from Québec: a researcher (Professor Benoît Marsan) and his team at the Université du Québec à Montréal (UQAM) have provided solutions to two problems which have been inhibiting the development of the very promising Graetzel solar cell that was developed in the 1990s in Switzerland. From the news item on Nanowerk a description of the problems,

Most of the materials used to make this cell are low-cost, easy to manufacture and flexible, allowing them to be integrated into a wide variety of objects and materials. In theory, the Graetzel solar cell has tremendous possibilities. Unfortunately, despite the excellence of the concept, this type of cell has two major problems that have prevented its large-scale commercialisation:

– The electrolyte is: a) extremely corrosive, resulting in a lack of durability; b) densely coloured, preventing the efficient passage of light; and c) limits the device photovoltage to 0.7 volts.

– The cathode is covered with platinum, a material that is expensive, non-transparent and rare. Despite numerous attempts, until Professor Marsan’s recent contribution, no one had been able to find a satisfactory solution to these problem

Now a description of the solutions,

– For the electrolyte, entirely new molecules have been created in the laboratory whose concentration has been increased through the contribution of Professor Livain Breau, also of the Chemistry Department. The resulting liquid or gel is transparent and non-corrosive and can increase the photovoltage, thus improving the cell’s output and stability.

– For the cathode, the platinum can be replaced by cobalt sulphide, which is far less expensive. It is also more efficient, more stable and easier to produce in the laboratory.

More details about the work and publication of the study are at Nanowerk.

Northeastern University and nano regulatory frameworks

According to a news item on Azonano, Northeastern University’s (Boston, MA) School of Law will be hosting a two-day conference on international regulatory frameworks for nanotechnology.

Leading international experts on the global regulation of nanotechnologies, including scientists, lawyers, ethicists and officials from governments, industry stakeholders, and NGOs will join in a two-day conference May 7-8, 2010 at Northeastern University’s School of Law.

The conference will identify best practices that address the needs of industries, the public and regulators. Speakers include representatives from the U.S. Environmental Protection Agency, the Brazil Ministry of Science and Technology, the Korean government, the International Conference of Chemicals Management and National Science Foundation-funded university-industry collaborations.

I checked out the law school’s conference website and noted a pretty good range of speakers from Asia, Europe, and North and South America. It can’t have been easy pulling such a diverse group together. Unfortunately, I didn’t recognize names other than two Canadian ones: Dr. Mark Saner and Pat Roy Mooney.

Saner who’s from Carleton University (Ottawa, Ontario) co-wrote a paper cited by Peter Julian (Canadian Member of Parliament) as one of the materials he used for reference when drawing up his recently tabled bill on nanotechnology regulation. (You can see Julian’s list here.) Saner, when he worked with the Council of Canadian Academies, was charged with drawing together the expert panel that wrote the council’s paper on nanotechnology. That panel put together a report (Small is Different: A Science Perspective on the Regulatory Challenges of the Nanoscale) that does a thoughtful job of discussing nanotechnology, regulations, the precautionary principle, etc. and which you can find here. (As I recall I don’t agree with everything as written in the report but it is, as I noted, thoughtful.)

As for Pat Roy Mooney, he’s the executive director for the ETC Group which is a very well-known (to many scientists and businesses in the technology sectors) civil society group. There’s an Oct. 2009 interview with Mooney here where he discusses (in English) nanotechnology during a festival in Austria.

Robert Fulford and nanotechnology

Canadian journalist and author, Robert Fulford just penned an essay/article about nanotechnology for the National Post. From the article,

Fresh bulletins regularly bring news of startling developments in this era’s most surprising and perhaps most poetic form of science, nanotechnology, the study of the unthinkably small.

It’s a pleasure to read as a literary piece. Fulford mostly concerns himself with visions of what nanotechnology could accomplish and with a book (No small matter) by Felice Frankel and George Whitesides which I first saw mentioned by Andrew Maynard on his 2020 Science blog here.