This week we will look at a new storage system for solar energy that will store that energy for up to 18 years. A really long life battery. We also examine a new heat pump that contains no moving parts. We investigate a magnetic microchip that uses less energy and retains memory in power outages. Finally we discover a new way to 3D print minute glass structures without flaws. As a bonus we look at what impact that AlphaFold has had on protein research.
Storage of Solar Energy
One oft cited criticism of solar power is that it is intermittent and that we need to store power for when it is needed. A team at Chalmers University of Technology in Sweden along with scientists from Shanghai Jiao Tong University have developed an energy system that stores solar energy in liquid form for up to 18 years.
The system uses specially developed molecules of carbon, hydrogen and nitrogen. When these molecules are hit by sunlight the atoms within the molecules are rearranged. This turns them into an energy rich isomer that can be stored in liquid form. The liquid will remain in this form for up to 18 years. The energy is released using a catalyst that returns the molecules to their original shape, thus releasing the stored energy as heat. A thermo electric generator then produces the electricity.
The generator is in the form of an ultra thin chip that could be integrated into electronics such as headphones, smart watches and phones. To date only small amounts of electricity have been generated however the system shows a lot of promise.
The proof of concept is quite small (0.1 nW). The team is now working on building an affordable commercial version of the system that could potentially be used in homes.
A Heat Engine with No Moving Parts
MIT researchers have developed a heat engine that has no moving parts. The engine converts heat into electricity with over 40% efficiency. This is better than traditional steam turbines that generate our power today (approximately 35%).
The heat engine is called a thermophotovoltaic (TPV) cell. It is similar to a solar panel’s photovoltaic cells. It captures high energy photons from a heat source and converts them into electricity. The device can generate electricity from a heat source of between 1,900C and 2,400C.
The device can be incorporated into grid scale thermal batteries. The system absorbs excess energy from solar or wind sources and stores that energy as heat in heavily insulated banks of hot graphite. The TPV cell would convert the heat into electricity when needed.
The advantage of this type of energy converter is that it can operate at higher temperatures with lower maintenance costs. Steam turbines are usually the first thing to breakdown and deteriorate in coal fired power stations. Most fusion and fission nuclear reactors also use steam turbines for power generation.
A new Transistor design for Microchips
Silicon based microchips are nearing their practical limits as we continue to shrink their size and pack more transistors onto a chip. Current transistor technology is about 25 silicon atoms in width. Heat is generated with these transistors so removing the heat to keep the transistors operating becomes a continually bigger problem.
At the machine level, computers rely on electric charges to determine if a transistor is on or off. The computer translates the on and off into a 1 or 0 and using binary code (the 1s and 0s are then used by other types of software). The software then translates every on and off into what we see on our screens.
A team from Nebraska University has developed a way to use the magnetic related properties of electrons (i.e. do the electrons point up or down) which can be read by the computer as a 1 or 0. Using graphene underlayed by magneto-electric chromium oxide they produced a spintronic-based transistor. When applying a positive voltage the spins of the chromium oxide pointed up. This signal can be read and used. A negative voltage flips the spin to downward.
The advantage of this development is that it can reduce the number of transistors needed to store data by up to 75% and reduce the overall energy required by the computer by 5%. The device will also retain memory during power loss. The process will work with other materials other than graphene. Now that the transistor has been developed the race is now on to find the set of materials with the greatest cost benefit payoff. Computers will continue to become faster and faster beyond the limits of silicon.
3D printed Glass
Researchers at UC Berkeley have developed a new way to print glass microstructures that is not only faster, it produces objects with greater optical quality and strength. They did this by expanding the capabilities of Computed Axial Lithography (CAL) which the same team developed 3 years ago.
Glass is the preferred medium when creating complex microscopic objects. This includes lenses for high quality cameras and endoscopes and for microfluidic devices used to analyze and measure minute amounts of liquids. Current methods of making these devices are expensive and slow.
CAL is different from traditional 3D printing processes. Currently 3D objects are printed one thin layer at a time until a 3D object has been created. CAL prints an entire object at one time. The team used lasers to project into a rotating volume of light sensitive material. The 3D light dose builds up until the desired shape has been created. This allows smooth surfaces and complex geometries without the layering associated with traditional 3D printing.
The process can print features in polymers down to 1/20 millionth of a meter. That is a quarter of the width of a human hair. Using glass, features 1/50 millionth of meter can be printed.
A special resin material containing nanoparticles of glass is surrounded by light sensitive binding liquid. Digital light projections from the printer solidify the binder, the printed object is then heated to remove the binder and fuse the particles together into a solid object of pure glass. Glass objects tend to break more easily when they contain flaws or cracks or have a rough surface. The CAL process reduces the flaws and produces glass with a more consistent strength reducing breakage.
The Use of AlphaFold
We first spoke about AlphaFold in December 2020. Google developed AlphaFold to help discover how proteins fold into their shapes. Shape is a very important variable in determining the function of proteins within the human body. Since the AlphaFold2 code was released in July 2021 the number of research articles citing AlphaFold has exploded. It is still early days however new applications follow on from new research.
This is a great illustration of how breakthrough developments can rapidly benefit society.
Paying it Forward
If you have a start-up or know of a start-up that has a product ready for market please let me know. I would be happy to have a look and feature the startup in this newsletter. Also if any startups need introductions please get in touch and I will help where I can.
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Till next week.