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The specter of counterfeit products is always a concern for any company that relies on other facilities to actually manufacture and assemble their products. From fake Rolex watches to fake iPhones to fake Louis Vuitton purses, large companies often spend millions to protect their intellectual property from criminals who copy and sell fake products to often unsuspecting consumers.

While it can be easy to be anti-corporate and turn a blind eye to this kind of theft, especially when the companies are large and extremely profitable, their concern goes far beyond the potential loss of profits. The fact is, most counterfeit products are vastly inferior to the real thing, and if a consumer doesn’t know that they are purchasing a fake then the company not only has a lost sale, but their reputation will take a hit based on something that they didn’t even produce.

Even as 3D printing continues to grow into a valid and profitable alternative manufacturing method to injection molding or large-scale mass production, there are still companies that see the threat of counterfeiting as a reason to stall the adoption of 3D printing technology. Realistically there is not much that can be done about pirated 3D models and individuals using home 3D printers to make fake products. Combating individual piracy has been woefully ineffective for the entertainment industry, and probably only encouraged more users to download electronic files illegally. It stands to reason that going after individual pirates will work just as well if the 3D printing industry makes an attempt to over-regulate and control the flow of 3D printable files.

DRM on 3D printable files is probably not going to be an effective deterrent.

DRM on 3D printable files is probably not going to be an effective deterrent.

Many of the solutions that are being floated as counter-counterfeiting measures don’t really seem especially feasible or sustainable. Adding DRM (digital rights management) or unlock code requirements to 3D files may slow down some users, but just as with DRM efforts on movies and video games, if someone can put a lock on something, someone can take that same lock off and teach others how to do it as well. These efforts may work in the short term, as the pool of users who are capable of breaking DRM on 3D printable files is smaller, and there isn’t really an outlet to disperse those illegal files yet. But as the industry grows it is going to be harder and harder for companies to control their intellectual property using these methods. I’m not really sure that there is much to be done on this end of the industry. Besides, there is an even greater counterfeiting problem brewing on the manufacturing side of the industry and it is far more important than individual piracy ever could be.

Counterfeit bolts.

Counterfeit bolts.

As with fake mass-produced consumer goods, mass-produced industrial parts are also counterfeited quite frequently. It may be more interesting to talk about fake purses, but a greater threat is products like fake screws, bolts, fittings and individual components. Many of the parts that are used to build our homes, businesses, vehicles and personal electronics use mass-produced components that manufacturers simply purchase in extremely large quantities. And all of those parts are held to very strict manufacturing guidelines that dictate how they can be used, what their maximum stress tolerances are and how they can be expected to perform.

When these types of components are forged, they are rarely made with the same quality of materials and often don’t even come close to performing as required. If these fake parts find their way unknowingly into the hands of manufacturers, who design products with these components’ manufacturing guidelines in mind, then the results could be catastrophic. There have been instances of airplanes and automobiles that have crashed due to the failure of lower quality, counterfeit parts. Buildings and homes are also at risk due to poor quality and counterfeited construction materials being used. It may seem odd, but cheaply made products that do not pass strict regulations are a huge business and lives can be lost to it.

3D printed Nike shoes with embedded InfraStructs.

3D printed Nike shoes with embedded InfraStructs.

With 3D printed components becoming more common, and eventually expected to be extremely common, counterfeit parts will pose a real risk. Using DRM, even if it was effective on a small scale, to prevent machines from making unauthorized parts is not going to matter when these parts can simply be 3D scanned and reproduced without the need for the original 3D model. The methods that need to be developed to combat this type of industrial counterfeiting will need to work in ways that DRM never will and identify the specific physical object as authentic. There are a few different methods that are currently being proposed, with varying probabilities of success.

The most likely option will be including RFID tags on 3D printed components that will identify an object as the real thing. The idea is that any part that doesn’t have an embedded RFID device in it — and they can easily be made small enough to easily be inserted inside of a 3D printed part — will automatically be identified as fake. The downside of this method is price, as the RFID tags themselves would be costly, as would the labor involved in inserting them. Testing for tags will also require specialized equipment that adds more cost to the authentication process. It is possible that a 3D printable material that would act as a tag called InfraStructs could be developed, but that would mean developing multiple materials that will be RFID reactive, which will be quite costly on the development side.

Subsurface fingerprinting with InfraTrac.

Subsurface fingerprinting with InfraTrac.

Another authentication option would be chemically tagging materials that can be detected with a handheld spectrometer. There are multiple companies providing these types of materials, but the most promising is a technique developed by InfraTrac. The Maryland-based company has developed a chemical that can be discreetly added to virtually anything without altering the chemical makeup of the material. For instance, parts can be 3D printed with a small subsurface “fingerprint” hidden in a discrete location. That mark alone would be printed with the material that has been treated with the chemical, and would easily identify the part as genuine. The material could also be printed as a single layer of the print with no mark, and no risk of altering the integrity of the part. Of course again this comes with it the need for specialized equipment in the form of the spectrometer and an actual machine that can 3D print with the standard material and the second, tagged material.

3D Printing II Heart 020516 maxresdefault

3D Printed Model of a Human Heart

One thing is very clear, there is a desire for additive manufacturing to be developed as an alternative to other mass production methods. That means the companies looking to use 3D printing to manufacture parts, and the 3D printing industry itself, are going to need to address the problem sooner rather than later. Determining which of these options is the ideal solution will not be an easy choice, as they both bring with them additional costs and challenges, but doing nothing simply isn’t an option.

 

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Nanowires 020316 bf8802f7297fd2bfea985c26d0b9a636_w1440

California is committed to 33 percent energy from renewable resources by 2020. With that deadline fast approaching, researchers across the state are busy exploring options.

Solar energy is attractive but for widespread adoption, it requires transformation into a storable form. This week in ACS Central Science, researchers report that nanowires made from multiple metal oxides could put solar ahead in this race.

One way to harness solar power for broader use is through photoelectrochemical (PEC) water splitting that provides hydrogen for fuel cells. Many materials that can perform the reaction exist, but most of these candidates suffer from issues, ranging from efficiency to stability and cost.

Peidong Yang and colleagues designed a system where nanowires from one of the most commonly used materials (TiO2) acts as a “host” for “guest” nanoparticles from another oxide called BiVO4. BiVO4 is a newly introduced material that is among the best ones for absorbing light and performing the water splitting reaction, but does not carry charge well while TiO2 is stable, cheap and an efficient charge carrier but does not absorb light well.

Together with a unique studded nanowire architecture, the new system works better than either material alone.

The authors state their approach can be used to improve the efficiencies of other photoconversion materials.

Synopsis

We report the use of Ta:TiO2|BiVO4 as a photoanode for use in solar water splitting cells. This host−guest system makes use of the favorable band alignment between the two semiconductors. The nanowire architecture allows for simultaneously high light absorption and carrier collection for efficient solar water oxidation.

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Metal oxides that absorb visible light are attractive for use as photoanodes in photoelectrosynthetic cells. However, their performance is often limited by poor charge carrier transport. We show that this problem can be addressed by using separate materials for light absorption and carrier transport. Here, we report a Ta:TiO2|BiVO4 nanowire photoanode, in which BiVO4 acts as a visible light-absorber and Ta:TiO2 acts as a high surface area electron conductor. Electrochemical and spectroscopic measurements provide experimental evidence for the type II band alignment necessary for favorable electron transfer from BiVO4 to TiO2. The host–guest nanowire architecture presented here allows for simultaneously high light absorption and carrier collection efficiency, with an onset of anodic photocurrent near 0.2 V vs RHE, and a photocurrent density of 2.1 mA/cm2 at 1.23 V vs RHE.

Introduction


Harnessing energy from sunlight is a means of meeting the large global energy demand in a cost-effective and environmentally benign manner. However, to provide constant and stable power on demand, it is necessary to convert sunlight into an energy storage medium.(1) An example of such a method is the production of hydrogen by photoelectrochemical (PEC) water splitting. The direct splitting of water can be achieved using a single semiconductor; however, due to the voltage requirement of the water splitting reaction and the associated kinetic overpotentials, only wide-band-gap materials can perform overall water splitting, limiting the efficiency due to insufficient light absorption.(2) To address this issue, a dual-band-gap z-scheme system can be utilized, with a semiconductor photoanode and photocathode to perform the respective oxidation and reduction reactions.(3) This approach allows for the use of lower-band-gap materials that can absorb complementary portions of the solar spectrum and yield higher solar-to-fuel efficiencies.(4, 5) In this integrated system, the charge flux is matched in both light absorbers of the photoelectrochemical cell. Therefore, the overall performance is determined by the limiting component. In most photoelectrosynthetic cells, this limiting component is the semiconductor photoanode.(6)
Metal oxides have been heavily researched as photoanode materials since few conventional light absorber materials are stable at the highly oxidizing conditions required for water oxidation.(7) However, the most commonly studied binary oxide, TiO2, has a band gap that is too large to absorb sunlight efficiently (∼3.0 eV), consequently limiting its achievable photocurrent.(8) While promising work has recently been done on stabilizing conventional light absorbers such as Si,(9) GaAs,(10) and InP,(11) the photovoltage obtained by these materials thus far has been insufficient to match with smaller-band-gap photocathode materials such as Si and InP in a dual absorber photoelectrosynthetic cell.(12, 13) Additionally, these materials have high production and processing costs. Small-band-gap metal oxides that absorb visible light and can be inexpensively synthesized, such as WO3, Fe2O3, and BiVO4, are alternative materials that hold promise to overcome these limitations.(14-16) Among these metal oxides, BiVO4 has emerged as one of the most promising materials due to its relatively small optical band gap of ∼2.5 eV and its negative conduction band edge (∼0 V versus RHE).(17, 18) Under air mass 1.5 global (AM1.5G) solar illumination, the maximum achievable photocurrent for water oxidation using BiVO4 is ∼7 mA/cm2.(16) However, the water oxidation photocurrent obtained in practice for BiVO4 is substantially lower than this value, mainly due to poor carrier transport properties, with electron diffusion lengths shorter than the film thickness necessary to absorb a substantial fraction of light.(17)
One approach for addressing this problem is to use two separate materials for the tasks of light absorption and carrier transport. To maximize performance, a conductive and high surface area support material (“host”) is used, which is coated with a highly dispersed visible light absorber (“guest”). This architecture allows for efficient use of absorbed photons due to the proximity of the semiconductor liquid junction (SCLJ). This strategy has been employed in dye sensitized (DSSC) and quantum dot sensitized solar cells (QDSSC).(19, 20) Using a host–guest scheme can improve the performance of photoabsorbing materials with poor carrier transport but relies upon appropriate band alignment between the host and guest. Namely, the electron affinity of the host should be larger, to favor electron transfer from guest to host without causing a significant loss in open-circuit voltage.(21) Nanowire arrays provide several advantages for use as the host material as they allow high surface area loading of the guest material, enhanced light scattering for improved absorption, and one-dimensional electron transport to the back electrode.(22) Therefore, nanowire arrays have been used as host materials in DSSCs, QDSSCs, and hybrid perovskite solar cells.(23-25) In photoelectrosynthetic cells, host–guest architectures have been utilized for oxide photoanodes such as Fe2O3|TiSi2,(26) Fe2O3|WO3,(27) Fe2O3|SnO2,(28) and Fe2TiO5|TiO2.(29) For BiVO4, it has been studied primarily with WO3|BiVO4,(30-32) ZnO|BiVO4,(33) and anatase TiO2|BiVO4.(34) While attractive for its electronic transport properties, ZnO is unstable in aqueous environments, and WO3 has the disadvantage of having a relatively positive flatband potential (∼0.4 V vs RHE)(14) resulting in potential energy losses for electrons as they are transferred from BiVO4 to WO3, thereby limiting the photovoltage of the combined system. Performance in the low potential region is critical for obtaining high efficiency in photoelectrosynthetic cells when coupled to typical p-type photocathode materials such as Si or InP.(12, 13) TiO2 is stable in a wide range of pH and has a relatively negative flat band potential (∼0.2 V vs RHE)(7) which does not significantly limit the photovoltage obtainable from BiVO4, while still providing a driving force for electron transfer. While TiO2 has intrinsically low mobility, doping TiO2 with donor type defects could increase the carrier concentration and thus the conductivity. Indeed, niobium and tantalum doped TiO2 have recently been investigated as potential transparent conductive oxide (TCO) materials.(35, 36) A host material with high carrier concentration could also ensure low contact resistance with the guest material.(37)
Using a solid state diffusion approach based on atomic layer deposition (ALD), we have previously demonstrated the ability to controllably and uniformly dope TiO2.(38) In this study we demonstrate a host–guest approach using Ta-doped TiO2 (Ta:TiO2) nanowires as a host and BiVO4 as a guest material. This host–guest nanowire architecture allows for simultaneously high light absorption and carrier collection efficiency, with an onset of anodic photocurrent near 0.2 V vs RHE, and a photocurrent of 2.1 mA/cm2 at 1.23 V vs RHE. We show that the synergistic effect of the host–guest structure results in higher performance than either pure TiO2 or BiVO4. We also experimentally demonstrate thermodynamically favorable band alignment between TiO2 and BiVO4 using spectroscopic and electrochemical methods, and study the band edge electronic structure of the TiO2 and BiVO4 using X-ray absorption and emission spectroscopies.

Article adapted from a American Chemical Society news release. To Read the FULL release, please click on the link provided below.

Publication: TiO2/BiVO4 Nanowire Heterostructure Photoanodes Based on Type II Band Alignment. Resasco, J et al. ACS Central Science (3 February, 2016): Click here to view.

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Graphene020216 NewsImage_34318

Graphene is a two-dimensional form of carbon, and successful demonstrations have been carried out by researchers to prove the possibility of interfacing graphene with nerve cells, or neurons, without affecting their integrity.

The demonstrations could help to develop graphene-based electrodes, which could be safely implanted into the brain. This study shows potential in restoring the sensory functions for individuals with Parkinson’s disease, epilepsy, amputees or paralyzed patients.

The Cambridge Graphene Centre and the University of Trieste in Italy together worked on this research, which was published in ACS Nano.

Other research teams have earlier demonstrated the possibility of using treated graphene to work with neurons. However very low signal to noise ratio was obtained from this interface. In this work, techniques were developed that allow the use of untreated graphene, and as a result they were able to retain the electrical conductivity of the material. This enables the graphene to function as a better electrode.

For the first time we interfaced graphene to neurons directly. We then tested the ability of neurons to generate electrical signals known to represent brain activities, and found that the neurons retained their neuronal signaling properties unaltered. This is the first functional study of neuronal synaptic activity using uncoated graphene based materials.

Professor Laura Ballerini, University of Trieste

It is possible to control some of the functions of the brain, by directly interfacing between the brain and the outside environment. For instance, it is possible to retrieve the sensory organs by evaluating the electrical impulses of the brain. This could help to control an amputee patient’s robotic arms or basic processes for paralyzed individuals, such as helping them with their speech and movement of objects surrounding them. It is also possible to control motor disorders like Parkinson’s disease or epilepsy when these electrical impulses are interfered with.

To make this possible, scientists have created electrodes that can be inserted deep into the human brain. These electrodes come into direct contact with the neurons and then send out electrical signals from the body to decode their meaning.

The issue that exists in the interface between neurons and electrodes is that the electrodes are not only expected to be extremely sensitive to electrical impulses, but they are also expected to be firm in the body without making changes in the tissue that is measured.

Often modern electrodes used for the tungsten-based or silicon-based interface suffer from complete or partial loss of signal over time. This occurs when scar tissues are created when the electrode is inserted, stopping the movement of the electrode with the natural movements of the brain due to its firm nature.

These issues can be solved using graphene due to its efficient stability, flexibility, conductivity, and biocompatibility within the body.

The researchers carried out experiments in the brain cell cultures of rats and concluded that interfacing with neurons was efficient in the case of untreated graphene electrodes. Based on the studies conducted on the neurons with electron microscopy and immunofluorescence, the researchers highlighted that the neurons continued to be healthy and transmitted normal electric impulses. Negative reactions that cause damage to the scar tissue were also not seen.

The research team considered this to be the first step in using pristine graphene-based materials instead of electrodes for a neuro-interface. The team plan to examine how different types of graphene, ranging from multiple layers to monolayers, are capable of affecting neurons. The researchers also plan to analyze whether changes made to the material properties of graphene can alter the neuronal excitability and synapses in unique ways.

Hopefully this will pave the way for better deep brain implants to both harness and control the brain, with higher sensitivity and fewer unwanted side effects.

Professor Laura Ballerini, University of Trieste

“We are currently involved in frontline research in graphene technology towards biomedical applications,” said Professor Maurizio Prato from the University of Trieste. “In this scenario, the development and translation in neurology of graphene-based high-performance biodevices requires the exploration of the interactions between graphene nano- and micro-sheets with the sophisticated signaling machinery of nerve cells. Our work is only a first step in that direction.”

These initial results show how we are just scratching the tip of an iceberg when it comes to the potential of graphene and related materials in bio-applications and medicine. The expertise developed at the Cambridge Graphene Centre allows us to produce large quantities of pristine material in solution, and this study proves the compatibility of our process with neuro-interfaces.

Professor Andrea Ferrari, Director of the Cambridge Graphene Centre

The research was financially supported by the European initiative, Graphene Flagship.

Source: http://www.cam.ac.uk/

Sun Solar 061015 Fusion BBkFITY

Video Interview with Professor Ted Sargent at the University of Toronto

With global climate change on the rise, finding ways to capture renewable energy sources is becoming more urgent. Today, our energy needs are largely being met by fossil fuels, such as oil and coal, but we are rapidly depleting these natural resources, and damaging our environment by burning them for fuel. One sustainable alternative is solar energy. Prof. Ted Sargent, an electrical engineer at the University of Toronto, is working on making a new paint-based solar cell that would be low-cost, lightweight, portable, and efficient, bringing sustainable electricity anywhere that it is needed.

We picture a world in which solar cells are so convenient. They are on a carpet that you can roll out onto your roof, or they are on a decal that you can stick on the side of a streetcar or stick on your car, you can stick on your airplane wing. And they can be kind of adhered to any surface. And they can be used to meet the power needs of that automobile or plane or helicopter or home or tent; and they are ubiquitous.

Unlike fossil fuels, Sargent explains, “the sun is this incredible, vast resource. We get more sun reaching the Earth’s surface everyday than we need to power the world’s energy needs. In fact, in an hour, we get enough to meet our energy needs for a year; it’s that abundant.” To achieve a better solar cell, Prof. Sargent is working at the interface of chemistry, physics, materials science, and electrical engineering to understand the relationships between light and electrons. He is developing a liquid for solar capture that can be applied as a paint, and that can be printed using roll-to-roll processes similar to those used to print newspapers. These paints would absorb sunlight and use it to generate electricity.

Prof. Sargent envisions solar cells that are so minimal that installing one might be as simple as unrolling a sheet onto a rooftop, or applying a decal to a streetcar or phone. “We picture a world in which solar cells are so convenient… They are so little in their consumption of materials that we change the paradigm of solar energy from one that takes planning, major capital investment, to one where it’s all over the place because it’s so compelling and convenient,” says Sargent.

How do you envision the future of energy and power? Let us know in the comments.


Prof. Ted Sargent
Prof. Ted Sargent holds the Canada Research Chair in Nanotechnology at the University of Toronto, where he also serves as Vice Dean for Research for the Faculty of Applied Science and Engineering. He is a Fellow of the Royal Society of Canada, a Fellow of the AAAS “for distinguished contributions to the development of solar cells and light sensors based on solution-processed semiconductors” and a Fellow of the IEEE “for contributions to colloidal quantum dot optoelectronic devices.” He is CTO of InVisage Technologies of Menlo Park, CA; and is a co-founder of Xagenic Inc.


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