SciTech #ScienceSunday Digest, 16/14.SCNT embryonic stem cells, universe from nothing, microrobots, nanowire photonics, biological glue, flexible wearables, programmable cells, gecko adhesives.1. First Embryonic Stem Cells from Adult Human Cells.
Human embryonic stem cells have finally been created with the somatic cell nuclear transfer technique using adult human cells whose nucleus is inserted into an egg cell the nucleus of which has been removed https://www.fightaging.org/archives/2014/04/somatic-cell-nuclear-transfer-achieved-in-adult-human-cells.php
. This is how Dolly the sheep was cloned in 1997, and should allow the creation of patient-specific stem cells for use in a range of therapeutic cell therapies. While this is a great advance there exist a number of different methods for achieving the same result such as cellular reprogramming to create induced pluripotent stem cells, and even last week we saw that just two factors were required to induce an adult stem cell to develop into an embryo. 2. A Universe from Nothing: A Mathematical Foundation.
An interesting result from theoretical physics constitutes the first mathematical proof that the Big Bang could have occured spontaneously from nothing due to quantum fluctuations https://medium.com/the-physics-arxiv-blog/ed7ed0f304a3
. The work is based on exploring new solutions to the Wheeler-DeWitt equation, which was originally proposed to combine quantum mechanics with relativity, and also building off Heisenberg’s uncertainty principle. The interesting twist here is (i) that the spontaneous and sustainable emergence of new Universes from nothing is dependent on the cosmological constant, which (ii) has to be replaced with a quantity known as the quantum potential,
a quantity that (iii) comes from pilot wave theory (hidden variables interpretation developed by David Bohm), and (iv) implying that the Universe and quantum mechanics are at heart entirely deterministic. This result also reminds me of the “time emerges from entanglement” work https://medium.com/the-physics-arxiv-blog/d5d3dc850933
. 3. Salt Water Flowing Over Graphene Generates Electricity.
Electricity has been generated from graphene simply by dragging a droplet of salt water over it http://gizmodo.com/pouring-saltwater-over-graphene-generates-electricity-1563379860
. When moving along the graphene the electrons in the salt water droplet desorb on one end of the graphene and absorb on the other, generating a tiny voltage that is proportional to the speed of the water; 30mV in the proof-of-concept. This is a tiny voltage and further work remains to be done, but what about powering low-power implanted devices with the flow of salty blood, or building large arrays of the devices for deployment in the ocean to harness wave and current power, or self-powered buoys, etc? 4. Manufacturing with Microrobots.
An innovative new approach to manufacturing electronics and small structures involves the use of swarms of independently controlled microrobots comprised of magnetic platforms with different manipulator arms or tools on top http://www.technologyreview.com/news/526601/microrobots-working-together-build-with-metal-glass-and-electronics/
. This video has a good overview Magnetically Actuated Micro-Robots for Advanced Manipulation Applications
. The bots move over a surface with embedded electronic coils, the control of which coordinates the movement and placement of up to 1,000 microrobots to date; different microrobots with different arms/tools are combined together in order to build and assemble more complex structures. Lots of possibilities and it’ll be interesting to see where they take this platform in future - even an automatic Lego builder would be a great demonstration. Work is progressing on controlled movement of nanomachines over surfaces too http://www.nanowerk.com/spotlight/spotid=35196.php
. 5. Detecting and Emitting Light with a Single Nanowire.
By straining gallium arsenide nanowires IBM can tune the devices to both absorb and emit light, efficiently functioning as single light emitting diodes or photodetectors http://spectrum.ieee.org/nanoclast/semiconductors/optoelectronics/ibm-combines-light-emission-and-detection-in-single-nanowire
and opening the possibility to reduce the complexity of nanophotonic chips. Materials strain engineering is a fascinating space where applying different forces to materials alters the atomic bond lengths and spacing, changing symmetries, and opening up novel and sometimes unintuitive electronic and photonic phenomena and applications. 6. The Benefits of Materials with Precisely Aligned Atoms.
We had a couple examples of such materials this week. First, the demonstration of compound semiconductor materials that comprised semimetal nanowires and nanoparticles made of erbium and antimony embedded into the semiconducting matrix of gallium antimonide http://spectrum.ieee.org/nanoclast/semiconductors/optoelectronics/nanostructures-could-bridge-gap-between-optics-and-electronics
. This results in the formation of a perfect and uninterrupted crystal lattice due to the fact that the atoms in the semimetal nanostructures match the pattern of those in the semiconductor, and allows a range of novel optoelectronic phenomena to be harnessed. Second, a new chemical vapour deposition process creates precisely layered van der Waals solids comprised of atomically thin two dimensional materials such as graphene, molybdenum disulfide, boron nitride, and tungsten diselenide that can result in optical and electrical performance improvements two orders of magnitude greater than bulk or single layered materials http://phys.org/news/2014-04-chemical-vapor-deposition-atomic-layer.html
. 7. Biological Glue and Wound Healing.
Polymer adhesive solutions containing silica and iron oxide nanoparticles have been shown to be extremely effective as “biological glue” http://phys.org/news/2014-04-strategy.html
. Proof-of-concept demonstrations included (i) quickly gluing deep wounds on skin within seconds to stop bleeding and create minimal scarring, (ii) repair living organs such as the liver that are difficult to suture, even after resection, and (iii) attach medical devices to living, beating hearts for quicker, more intimate, and less invasive monitoring and diagnosis. The nanoparticles can themselves be metabolised by the animal and these materials offer applications across a broad spectrum of clinical scenarios. 8. Flexible Adhesive Wearable Devices.
A new wearable electronic patch is flexible, stretchable, adhesive to skin, and incorporates standard silicon chips, microcontrollers, microfluidics, flexible wire designs, and sensors http://singularityhub.com/2014/04/18/new-method-points-to-cheaper-more-flexible-wearable-computers/
. The new design pursues a compartmentalised, or modular,
design strategy in order to facilitate rapid development and compatibility with a broad range of off-the-shelf components and relevant standards. Stuck to the skin such devices can measure biometric data much more clearly than devices that merely sit (and can jostle) on top of the skin. The group hopes that future versions will be even more user-friendly and allow continuous health monitoring of a large range of different measurements. This could also be a very interesting biohacking platform. 9. Gecko Skin Adhesives Getting Better.
An improved version of “Geckskin”, a reusable adhesive material that mimics gecko’s ability to stick to surfaces has been developed that can adhere even heavy loads onto vertical surface materials ranging from wood to glass http://phys.org/news/2014-04-versatile-version-geckskin-gecko-like-adhesives.html
. A video demonstration can be found here Geckskin on Everything
. The fabrication process allows tuning of the material components in order to optimise for different applications, although it’s yet to be seen whether that will be for robotics, spider-man suits, home appliances, etc. 10. Modular Extracellular Sensor Architecture.
Human cells have been engineered to produce a protein biosensor that sits on the cell surface, which is programmed to sense specific molecules and trigger a corresponding gene expression program in the cell’s nucleus http://www.mccormick.northwestern.edu/news/articles/2014/04/building-smart-cell-based-therapies.html
. The idea of course is to use such systems to create programmable therapeutics able to travel through the patient's body to selectively target metabolites, cells, or diseased tissues of interest. The current platform is modular, allowing additional biosensor + gene expression circuits to be added to the same cell and so enabling increasingly sophisticated programs to be built. For example cells could be programmed to turn on a gene when one protein is sensed and not another, allowing cells to specifically kill certain tumour cells. SciTech Digest just debuted on Medium too: https://medium.com/@SciTechDigest +ScienceSunday
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