Tag Archives: viruses

Touchless displays with 2D nanosheets and sweat

Swiping touchscreens with your finger has become a dominant means of accessing information in many applications but there is at least one problem associated with this action. From an Oct. 2, 2015 news item on phys.org,

While touchscreens are practical, touchless displays would be even more so. That’s because, despite touchscreens having enabled the smartphone’s advance into our lives and being essential for us to be able to use cash dispensers or ticket machines, they do have certain disadvantages. Touchscreens suffer from mechanical wear over time and are a transmission path for bacteria and viruses. To avoid these problems, scientists at Stuttgart’s Max Planck Institute for Solid State Research and LMU Munich have now developed nanostructures that change their electrical and even their optical properties as soon as a finger comes anywhere near them.

Here’s what a touchless screen looks like when tracking,

Touchless colour change: A nanostructure containing alternating layers of phosphatoantimonate nanosheets and oxide ... [more] © Advanced Materials 2015/MPI for Solid State Research

Touchless colour change: A nanostructure containing alternating layers of phosphatoantimonate nanosheets and oxide … [more]
© Advanced Materials 2015/MPI for Solid State Research

An Oct. 1, 2015 Max Planck Institute press release, which originated the news item, gives technical details,

A touchless display may be able to capitalize on a human trait which is of vital importance, although sometimes unwanted: This is the fact that our body sweats – and is constantly emitting water molecules through tiny pores in the skin. Scientists of the Nanochemistry group led by Bettina Lotsch at the Max Planck Institute for Solid State Research in Stuttgart and the LMU Munich have now been able to visualize the transpiration of a finger with a special moisture sensor which reacts as soon as an object – like an index finger – approaches its surface, without touching it. The increasing humidity is converted into an electrical signal or translated into a colour change, thus enabling it to be measured.

Phosphatoantimonic acid is what enables it to do this. This acid is a crystalline solid at room temperature with a structure made up of antimony, phosphorous, oxygen and hydrogen atoms. “It’s long been known to scientists that this material is able to take up water and swells considerably in the process,” explained Pirmin Ganter, doctoral student at the Max Planck Institute for Solid State Research and the Chemistry Department at LMU Munich. This water uptake also changes the properties of the material. For instance, its electrical conductivity increases as the number of stored water molecules rises. This is what enables it to serve as a measure of ambient moisture.

A sandwich nanomaterial structure exposed to moisture also changes its colour

However, the scientists aren’t so interested in developing a new moisture sensor. What they really want is to use it in touchless displays. “Because these sensors react in a very local manner to any increase in moisture, it is quite conceivable that this sort of material with moisture-dependent properties could also be used for touchless displays and monitors,” said Ganter. Touchless screens of this kind would require nothing more than a finger to get near the display to change their electrical or optical properties – and with them the input signal – at a specific point on the display.

Taking phosphatoantimonate nanosheets as their basis, the Stuttgart scientists then developed a photonic nanostructure which reacts to the moisture by changing colour. “If this was built into a monitor, the users would then receive visible feedback to  their finger motion” explained Katalin Szendrei, also a doctoral student in Bettina Lotsch’s group. To this end, the scientists created a multilayer sandwich material with alternating layers of ultrathin phosphatoantimonate nanosheets and silicon dioxide (SiO2) or titanium dioxide nanoparticles (TiO2). Comprising more than ten layers, the stack ultimately reached a height of little more than one millionth of a metre.

For one thing, the colour of the sandwich material can be set via the thickness of the layers. And for another, the colour of the sandwich changes if the scientists increase the relative humidity in the immediate surroundings of the material, for instance by moving a finger towards the screen. “The reason for this lies in the storage of water molecules between the phosphatoantimonate layers, which makes the layers swell considerably,” explained Katalin Szendrei. “A change in the thickness of the layers in this process is accompanied by a change in the colour of the sensor – produced in a similar way to what gives colour to a butterfly wing or in mother-of-pearl.”

The material reacts to the humidity change within a few milliseconds

This is a property that is fundamentally well known and characteristic of so-called photonic crystals. But scientists had never before observed such a large colour change as they now have in the lab in Stuttgart. “The colour of the nanostructure turns from blue to red when a finger gets near, for example. In this way, the colour can be tuned through the whole of the visible spectrum depending on the amount of water vapour taken up,” stressed Bettina Lotsch.

The scientists’ new approach is not only captivating because of the striking colour change. What’s also important is the fact that the material reacts to the change in humidity within a few milliseconds – literally in the blink of an eye. Previously reported materials normally took several seconds or more to respond. That is much too slow for practical applications. And there’s another thing that other materials couldn’t always do: The sandwich structure consisting of phosphatoantimonate nanosheets and oxide nanoparticles is highly stable from a chemical perspective and responds selectively to water vapour.

A layer protecting against chemical influences has to let moisture through

The scientists can imagine their materials being used in much more than just future generations of smartphones, tablets or notebooks. “Ultimately, we could see touchless displays also being deployed in many places where people currently have to touch monitors to navigate,” said Bettina Lotsch. For instance in cash dispensers or ticket machines, or even at the weighing scales in the supermarket’s vegetable aisle. Displays in public placesthat are used by many different people would have distinct hygiene benefits if they were touchless.

But before we see them being used in such places, the scientists have a few more challenges to overcome. It’s important, for example, that the nanostructures can be produced economically. To minimize wear, the structures still need to be coated with a protective layer if they’re going to be used in anything like a display. And that, again, has to meet not one but two different requirements: It must protect the moisture-sensitive layers against chemical and mechanical influences. And it must, of course, let the moisture pass through. But the Stuttgart scientists have an idea for how to achieve that already. An idea they are currently starting to put into practice with an additional cooperation partner on board.

Dexter Johnson’s Oct. 2, 2015 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website) provides some additional context for this research (Note: A link has been removed),

In a world where the “swipe” has become a dominant computer interface method along with moving and clicking the mouse, the question becomes what’s next? For researchers at Stuttgart’s Max Planck Institute for Solid State Research and LMU Munich, Germany, the answer continues to be a swipe, but one in which you don’t actually need to touch the screen with your finger. Researchers call these no-contact computer screens touchless positioning interfaces (TPI).

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

Touchless Optical Finger Motion Tracking Based on 2D Nanosheets with Giant Moisture Responsiveness by Katalin Szendrei, Pirmin Ganter, Olalla Sànchez-Sobrado, Roland Eger, Alexander Kuhn, and Bettina V. Lotsch. Advanced Materials DOI: 10.1002/adma.201503463 Article first published online: 22 SEP 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Protein cages, viruses, and nanoparticles

The Dec. 19, 2012 news release on EurekAlert about a study published by researchers at Aalto University (Finland) describes a project where virus particles are combined with nanoparticles to create new metamaterials,

Scientists from Aalto University, Finland, have succeeded in organising virus particles, protein cages and nanoparticles into crystalline materials. These nanomaterials studied by the Finnish research group are important for applications in sensing, optics, electronics and drug delivery.

… biohybrid superlattices of nanoparticles and proteins would allow the best features of both particle types to be combined. They would comprise the versatility of synthetic nanoparticles and the highly controlled assembly properties of biomolecules.

The gold nanoparticles and viruses adopt a special kind of crystal structure. It does not correspond to any known atomic or molecular crystal structure and it has previously not been observed with nano-sized particles.

Virus particles – the old foes of mankind – can do much more than infect living organisms. Evolution has rendered them with the capability of highly controlled self-assembly properties. Ultimately, by utilising their building blocks we can bring multiple functions to hybrid materials that consist of both living and synthetic matter, Kostiainen [Mauri A. Kostiainen, postdoctoral researcher] trusts.

The article which has been published in Nature Nanotechnology is free,

Electrostatic assembly of binary nanoparticle superlattices using protein cages by Mauri A. Kostiainen, Panu Hiekkataipale, Ari Laiho, Vincent Lemieux, Jani Seitsonen, Janne Ruokolainen & Pierpaolo Ceci in Nature Nanotechnology (2012) doi:10.1038/nnano.2012.220  Published online 16 December 2012

There’s a video demonstrating the assembly,

From the YouTube page, here’s a description of what the video is demonstrating,

Aalto University-led research group shows that CCMV virus or ferritin protein cages can be used to guide the assembly of RNA molecules or iron oxide nanoparticles into three-dimensional binary superlattices. The lattices are formed through tuneable electrostatic interactions with charged gold nanoparticles.

Bravo and thank  you to  Kostiainen who seems to have written the news release and prepared all of the additional materials (image and video). There are university press offices that could take lessons from Kostiainen’s efforts to communicate about the work.

Black Rooster and nanotechnology

The entertainment industry seems to be using nanotechnology as a ready-to-hand narrative device (as per my NEW-GEN Oct. 17, 2011 posting and my Deus Ex: Human Revolution Aug. 18, 2011 posting, amongst others). The latest offering is Patient Zero from Black Rooster Creations. From the Oct. 18, 2011 media release on PRWeb,

Black Rooster Creations has launched its website with a viral campaign and three major book releases written by screenwriter Jim Beck featuring zombies, superheroes, and yes, even bugs.

The first release, Patient Zero, serves as a cautionary tale that mixes old school zombies with new school technology. Narrated by the zombie virus itself, the story follows single father Robert Forrester, who is brought back to life as one of the living dead after a botched experiment involving nanotechnology. [emphasis mine] His transformation is slow, first appearing as a skin rash and advanced arthritis, and he quickly begins to lose control.

Beck stated, “The idea for Patient Zero came to me after ingesting numerous forms of zombie lore and realizing that many of them shared the same basic formula of an unexplained outbreak, followed by a group of people trying to survive. I wanted to tell a more personal story about a single father trying to protect his son and defend their home while coming to grips with his own transformation. I also liked the contrast between zombification and nanotechnology, and telling the story from the point of view of the virus will provide readers with an insight rarely seen in the world of zombies.”

I could be wrong here but I don’t have the impression that this work is well grounded in science still, that doesn’t mean that it won’t be fun. You can go to the Black Rooster Creations website to get more information.

Viruses as manufacturing plants

In her January 2011 TEDx talk at Caltech (California Institute of Technology), MIT (Massachusetts Institute of Technology) Professor Angela Belcher talks about using viruses to grow batteries that don’t require toxic materials for their production or produce toxic materials themselves. It’s similar to biomimicry in that the reference point is nature but rather than trying to simulate nature using synthetic materials this work focuses on tweaking nature so that something like a virus can be used to create something new, e.g., a battery, a solar cell, etc.


A Sept. 25, 2011 article by Karen Weintraub on the BBC News website offers further insight into Belcher’s work,

Prof Belcher’s work unites the inanimate world of simple chemicals with proteins made by living creatures, a mash-up of the living and the lifeless.

She is motivated, she says, by a simple question: “How do you give life to non-living things?”

Like the abalone collecting its materials in shallow water and then laying them down like bricks in a wall, Belcher takes basic chemical elements from the natural world: carbon, calcium, silicon, zinc. Then she mixes them with simple, harmless viruses whose genes have been reprogrammed to promote random variations.

The resulting new materials just might address some of our most vexing problems.

The distinctiveness of Prof Belcher’s work, colleagues say, lies in her use of biology to synthesise new materials for such a wide range of uses, to develop an entirely new method for producing entirely novel materials.

“Her methodologies for directing and assembling materials I think will be unique,” says Yet-Ming Chiang, an MIT professor who collaborates with Prof Belcher on battery research. “I think 50 years from now, we’ll look back on biology as an important part of the toolkit in manufacturing… we’ll look back and say this is one of the fundamental tools we developed in this century.”

As I’ve been thinking about life/nonlife (in the context of human enhancement and memristors), this works offers me additional food for thought. Meanwhile, the TEDx talk and the Weintraub article point to some of the vast difference between scientists and lay people (general public). Belcher references life/nonlife quite casually, almost in passing. This could be quite disturbing to folks who believe there’s a distinct difference. The disturbances don’t stop there.

In the first place, viruses do not have a good reputation. When you add in the problems with calling your work biotechnology (as Belcher does in her TEDx talk), the stage is set for some interesting possibilities. If that isn’t enough, Belcher’s work comes perilously close to Eric Drexler’s self-assembling nano entities and the spectre of ‘grey’ or ‘green’ goo. It’s been a while since the big scares over genetically modified organisms (GMO), I wonder if scientists have forgotten or perhaps they don’t realize just how much conflicting (and often frightening) information is still being pushed at the general public. As for breaching the life/nonlife boundaries, that could be a whole other mess.

Viruses mine for copper at the University of BC; microscopy at the University of Victoria; the Henry Louis Gates Jr. affair, human nature, & human enhancement

Professor Scott Dunbar at the University of British Columbia’s (Canada) Norman B. Keevil Institute of Mining Engineering needed to partner with colleagues Sue Curtis and Ross MacGillivray from the Centre for Blood Research and the Department of Biochemistry and Molecular Biology after (from the media release on Nanowerk News),

“I read an article about bacteriophage – viruses that infect bacteria – being used to create nanodevices in which proteins on the phage surface are engineered to bind to gold and zinc sulfide,” says Dunbar. “And it struck me: if zinc sulfide, why not copper sulfide? And if so, then it might be possible to use these bio-engineered proteins to separate common economic sulfide minerals from waste during mineral extraction.”

Together the researchers have developed a procedure called “biopanning.” It’s a kind of genetic engineering which could lead to some useful applications.

It turns out that the phage that bind to a mineral do affect the mineral surfaces, causing them to have a different electrical charge than other minerals. The proteins on the phage also form links to each other leading to aggregation of the specific sulfide particles. “The physical and chemical changes caused by phage may be the basis for a highly selective method of mineral separation with better recovery. Another possible application is bioremediation, where metals are removed from contaminated water” says Dunbar.

In other BC news, the University of Victoria (Canada) will be getting a new microscope which senses at subatomic levels. (From the media release on Azonano),

The new microscope-called a Scanning Transmission Electron Holography Microscope (STEHM) — will use an electron beam and holography techniques to observe the inside of materials and their surfaces to an expected resolution as small as one-fiftieth the size of an atom.

This is being done in collaboration with Hitachi High-Technologies which is building the microscope in Japan and installing it at U Vic in late 2010. The microscope will be located in a specially adapted room where work to prepare and calibrate it will continue until it becomes operational sometime in 2011.

After my recent series on robots and human enhancement, I feel moved to comment on the situation in the US vis a vis Henry Louis Gates, Jr. and his arrest by the police officer, James Crowley. It’s reported here and elsewhere that neither the recording of the 911 call nor the concerned neighbour who made the call support Sergeant Crowley’s contention that the two men allegedly breaking into the house were described as ‘black’.

Only the participants know what happened and I don’t fully understand the nuances of race, class, and cultural differences that exist in the US so I can’t comment on anything other than this. It is human to hear what we expect to hear and I have an example from a much less charged situation.

Many years ago, I was transcribing notes from a taped interview (one of my first) for an article that I was writing for a newsletter. As I was transcribing, I noticed that I kept changing words so that the interview subject sounded more like me. They were synonyms but they were my words not his. Over the years I’ve gotten much better at being more exact but I’ve never forgotten how easy it is to insert your pet words (biased or not) when you’re remembering what someone said. Note: I was not in a stressful situation and I could rewind and listen again at my leisure.

I hope that Crowley and Gates, Jr. are able to work this out in some fashion and I really hope that it is done in a way that is respectful to both men and not a rush to a false resolution for the benefit of the cameras. For a more informed discussion of the situation, you may find this essay by Richard Thompson Ford  in Slate helpful. It was written before the recording of the 911 call was made public but I think it still stands.

My reason for mentioning this incident is that human nature tends to assert itself in all kinds of situations including the building of robots and the debates on human enhancement, something I did not mention in my series posted (July 22 – 24, 27, 2009).