News and Events

Weekly top 10 selection of scientific and technological advances-27th Oct

Mark BruceMonday, 28 October 2013.

Source: SciTech Digest 37

A Top 10 selection of scientific and technological advances each week compiled by ITEK's Commercial Manager Mark Bruce.

This week: 

Lego-Microfabrication, DNA-nanoparticle assembly, functional cell implants...and more.

1. Block-by-Block Lego Style Microfabrication.
A new systems allows controlled modulation of the adhesion forces acting on a polymeric stamp and makes possible Lego-like assembly and microfabrication of micro-objects and blocks: http://www.nanowerk.com/spotlight/spotid=32887.php. Adhesive forces, which vastly dominate gravity at the microscale, have plagued efforts to create effective micro-gripper and placement systems. The new technique circumvents these problems by enabling modulation of the force as needed, leading to an architecture that can accurately pick-and-place microstructures from donor to receiver substrates. The technique was proven by creating complex MEMS devices and next steps will involve the creation of more complex tools for microfabrication.

2. DNA Self-Assembly of Nanoparticles into Functional Materials.
A new technique enables the coating of naoparticles with a standard material that DNA strands can bind to, and by designing the DNA sequence complementary base-pairing allows the self-assembly of different nanoparticles into precisely structured materials http://www.kurzweilai.net/mix-and-match-nanoparticles-self-assemble-into-exotic-multifunctional-materials-guided-by-dna. Currently the structures can have billions of nanoparticles assembled in ordered arrays and multiple variables to optimise numerous parameters. The combination of magnetic, catalytic, fluorescent, and other nanoparticles is expected to enable the creation of a whole new range of materials. If they can get to tens of micrometers then #1 above may facilitate the fabrication of larger material substrates.

3. Optically-Activated Genetically-Modified Cells in Hydrogel Implants.
Researchers have implanted a hydrogel implant containing genetically engineered cells that produce a compound that stimulates the secretion of insulin when exposed to light http://www.newscientist.com/article/dn24438-cyborg-gel-implant-fights-diabetes-with-light.html. This is a pretty powerful study. Different genetically engineered cells were explored, with the insulin stimulating cells successfully stabilising the blood glucose levels of mice. Other cells alerted people - by fluorescing - to the presence of cadmium poisoning in the mouse. A pretty amazing combination of lots of different technologies into a functional platform that has nearly endless applications. It could also be combined with this device http://phys.org/news/2013-10-blood-sugar.html able to measure glucose levels (and presumably many other things) in the blood simply by shining an infrared laser through the skin.

4. Engineered Cellular Nanopore Controls Passage of Specific DNA.
A nanopore has been designed that lodges into the wall of cell and which only allows the passge of specific DNA sequences into the cell http://phys.org/news/2013-10-nanopore-cellular-doorway-drug.html. The nanopore is programmable in the sense that by specifying the DNA sequence attached to the pore you can specify which complementary sequence is allowed passage through the pore into the cell. Interesting possibilities arise when considering a cell engineered to produce various different pores that allow the cell to be programmed to do different things when different DNA sequences are added to the environment. Meanwhile another nanopore sensor can accurately detect and distinguish epigenetic methylation changes on genes of interest http://www.nanowerk.com/spotlight/spotid=32808.php.

5. Electrical Diode Created with Two-Dimensional Atom-Thick Materials.
In recent work reveals molybdenum disulfide has been combined with carbon nanotubes to create a p-n junction diode, a device that comprises the core component of solar cells, LEDs, photodetectors, and lasers
http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/twodimensional-materials-tackle-the-ubiquitous-pn-junction-diode. Not only does such a device represent a big step in device miniaturisation, but this architecture also highly sensitive and predictably tunable to different wavelengths of light depending on the desired application. Plenty of applications to explore.

6. IBMs Liquid Cooled and Liquid Fueled Brain-Inspired Computer.
IBM revealed a prototype brain-inspired computer that is cooled and powered by the equivalent of “electronic blood” http://www.bbc.co.uk/news/science-environment-24571219. The 3D stacked chips are integrated with tiny water pipes that cool the circuits and result in 40% lower electricity consumption. The fluid itself is a vanadium-based electrolyte that carries energy that the chips can use for power via redox reactions. The principle is actually designed to mimic another natural phenomenon observed in animals, that of allometric scaling, in which metabolic power shows well-known efficiency improvements with increasing animal size.

7. Implanted Spinal Stimulation Circumvents Paralysis.
Spinal implant electrode arrays and pulse generators have been shown - in paralysed humans - to restore some leg muscle movement, bladder, bowel, and sexual functions http://spectrum.ieee.org/biomedical/devices/spinal-stimulation-gets-paralyzed-patients-moving. The implanted electrodes target different nerves and muscle groups; getting one particular muscle to activate is quite easy but the challenge remains in coordinating many different electrical patterns to generate complex and useful behavior for the patient - a way to go but still very promising and the result of groundbreaking animal studies. Check the video to see paralysed rats and humans moving again Fighting Paralysis With Electricity. Sensory feedback from nerves in the legs turn out to be key. In related news deep brain stimulation of rats improves walking and swimming in paralysed rats by recruiting intact nerves http://spectrum.ieee.org/tech-talk/biomedical/devices/deep-brain-stimulation-improves-paralyzed-rats-gait.

8. Competition in Workplace Robotics Heating Up.
Startup company Unbounded Robotics launched their one-armed UB1 robot that is intended for roll-out to research laboratories and workplaces http://www.technologyreview.com/news/520456/why-this-might-be-the-model-t-of-workplace-robots/. Looking like an evolution of the PR2 platform and proposing to sit in a similar space to Rethink’s Baxter series, the focus is definitely on getting robots out of the lab and enabling productive business use. While the UB1 sports only the one arm it is mobile and potentially more versatile (and cheaper) than current systems; tasks requiring two arms can be accomplished by having two UB1s coordinate their motions and work together.

9. Characterisation of Non-Uniform Cortical Columns.
New research on rats has found that the structure of of individual cortical columns in the brain - the basic repeating functional unit of the neocortex - can differ between different cortical areas and different animals http://www.pnas.org/content/early/2013/10/02/1312691110.full.pdf. The structures were thought to be uniform, but this work looked at the area of the brain responsible processing information from the whiskers, at individual columns responsible for individual whiskers and saw marked differences. Basically, different whiskers were represented by columns of a different size. While some have claimed that this is a problem for human brain models, maps, and simulations championed by Markram and others, I disagree rather strongly - looking into the study I think the alterations to such models would be trivial. 

10. All Graphene Computer Chips.
A design for a computer chip has been developed in which all the components are made of graphene http://www.extremetech.com/computing/169583-all-graphene-computer-chip-could-steer-us-past-the-22nm-bottleneck. The proposal hinges on exploiting the property of graphene to behave differently depending on its thickness; narrow ribbons are semiconducting and could make transistors while thick ribbons are metallic and could make good gates and chip interconnects. The design looks great in theory - just need to see them reduce it to practice and make a functional prototype to give us a boost in chip speeds to the THz range.