Nanotech Digest - March 2017

Taiwanese semiconductor manufacturer plans to make 5nm chips

Taiwan Semiconductor Manufacturing Company has leaked plans (at the company’s supply chain meeting, as reported in the Taipei Times and elsewhere) to start ‘risk production’ of its 5-nanometre technology in the first half of 2019, which according to typical industry timelines would mean mass production by 2020. The chips would allow for more functionality and processing power within a smaller structure than today’s 10nm technology, and the 7nm technology due for mass production next year, and could have applications in smartphones and data centre processors.

Membrane manufacturing method

University of Minneapolis researchers have developed a one-step crystal growth process to create zeolite nanosheets. The zeolite (silicate crystals with molecular pores) nanosheets can be used as molecular sieves having applications in industries requiring chemical separation such as the petrochemical and chemical industries. The process the researchers developed is to seed nanocrystals so that they expand in size and develop facets, that sprout twin outgrowths that become the nanosheet. The sheets begin from one corner and encircle the seed crystal creating a uniform, thin (five nanometres thick and several micrometres wide) sheet of zeolite. The researchers claim that their method is a cheaper, simpler method of creating zeolite sheets than current methods. 

Amoeba robots could deliver drugs

Scientists from Tohoku University and Japan Advanced Institute of Science and Technology have developed an amoeba-like molecular robot that can alter its shape based in response to specific molecular signalling. The robots are formed of a body, an actuator and a clutch (an actuator-control device) made of DNA molecules.  When activated by light the robot will release a signal molecule, disengaging the clutch and halting the shape changing. The initiation of shape change via an input was also demonstrated. In the future it is envisaged that the bots could be used as drug delivery systems. 

Tufts manipulate materials to make them stronger

Tufts University researchers have developed a technique to convert silk into programmable complex materials. Through combining bottom-up self-assembly – common in nature – with directed, top-down assembly the team could control geometry, micro-mechanical constraints, and solvent-removal dynamics. In creating the complex silk material the scientists first created a centimetre scale silicone mould patterned with micro-scale features into which was injected an aqueous fibroin protein gel refined from silk worm cocoons. The gel was then stressed by the addition of water and ethanol, or by an external source by deformation of the mould. Once the material dried the silk’s protein dried into a beta-sheet crystal. The final material’s shape and properties were all controlled by the scientists. A web of fibres made this way could hold 4,000 times their own weight. 

China building nanotech facility

China is developing a large multifunctional development facility to focus on nanotechnology, powerful computers, and intelligent robots. The facility in Suzhou, Jiangsu, will be able to mimic the vacuum conditions found in space for exploring technology routes of nanoscale device production, testing and materials growth. The facility has received CNY320 million (USD46.5 million) with a total investment of CNY1.5 billion (USD217 million). Construction began in 2014 and is expected to be finished in 2018. It will have 500 metres of ultra-high vacuum pipelines connecting 100 pieces of equipment. 

Returning sight to rats

University of California San Diego and start-up Nanovision Biosciences have demonstrated a nanoscale prosthesis capable of re-activating retinal activity in rats. The prosthesis is composed of arrays of light-sensitive silicon nanowires that electrically stimulate the retinal cells which can provide higher resolution than other retinal prostheses. The device can be surgically implanted into the sub-retinal cavity. Power is provided wirelessly through an induction. Tests are ongoing to better categorise the electrophysical function of the parts of the brain that process visual information in response to the implant’s stimulation.  

Quantum dots for lasers

An international team of scientists from American and Canadian universities have developed colloid solutions containing quantum dots (QDs – very small semiconductor particles) that enable steady state lasing. Quantum dots can absorb energy, reemitting it as light – the frequency of that light depends on the dot’s physical properties. The team’s colloidal QDs are particularly suitable for use as laser materials as they can be tuned, by manipulating their size, to emit a specific colour. This contrasts with traditional methods of laser manufacture – the teams claim - where the materials used tend to limit light frequencies to specific or small ranges of frequencies. 
The team from the University of Toronto mixed together liquid solutions containing quantum dot precursors that reacted to produce solid quantum dots suspended in the liquid. The scientists say that this process of making solution-based QDs would be scalable because the techniques are already used in the printing industry. The Toronto team altered the shape of the quantum dots, making them oblate spheroids, reducing the amount of energy needed to trigger a laser – this is important because quantum dots typically need a lot of energy to act as lasers (and lose a lot of heat as energy). This also means that the quantum dot is less likely to overheat - opening up the possibility for the laser to be fired continually. 

Flexiglass

Brigham Young University scientists have developed a technology that allows glass to bend and flex when exposed to an electrical current.  The degree of bending and folding of the silica thin films was determinable by voltage: by applying 150V the material can move 100 nanometres. The scientists believe that this phenomenon could be useful in the construction of lab-on-a-chip devices that can function at the nanoscale which could move, trap and analyse things like proteins, viruses or DNA. 

Making gearboxes go further

TriboTEX is crowdfunding its anisotropic flat nanoparticle, DuoLife, that is able to reduce friction and repair damage in engines, ball bearings and gears. The product is said to reduce friction tenfold compared to not using any product. It acts as a self-forming film, has two functionally different sides –  one slippery the other rough – and could be used in industrial equipment such as wind turbines, according to the company. 

Writing to magnetic atoms

Scientists at IBM have created a single atom magnet that can act as a storage device. The device stored one bit of data on the magnet. This compares favourably with other hard drives which might use as many as 100,000 atoms to store the same amount of information.  IBM says that using this tech would enable the 35 million song library of iTunes to be stored on a credit card sized device. In the study, IBM also demonstrated the reading and writing of information to two magnetic atoms spaced one nanometre apart by applying electric current.

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