Solar Panels for Cells

New research in the journal Nature Aging takes a page from the field of renewable energy and shows that genetically engineered mitochondria can convert light energy into chemical energy that cells can use, ultimately extending the life of the roundworm C. elegans.  While the prospect of sunlight-charged cells in humans is more science fiction than science, the findings shed light on important mechanisms in the aging process.

Caenorhabditis elegans (C. elegans) has been the source of major discoveries in molecular and cell biology

We know that mitochondrial dysfunction is a consequence of aging,” said Andrew Wojtovich, Ph.D., associate professor of Pharmacology & Physiology at the University of Rochester Medical Center and senior author of the study.  “This study found that simply boosting metabolism using light-powered mitochondria gave laboratory worms longer, healthier lives.  These findings and new research tools will enable us to further study mitochondria and identify new ways to treat age-related diseases and age healthier.”

Mitochondria are organelles found in most cells in the body.  Often referred to as cellular power plants, mitochondria use glucose to produce adenosine triphosphate (ATP), the compound that provides energy for key functions in the cell, such as muscle contraction and the electrical impulses that help nerve cells communicate with each other.

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How to Produce Drinkable Water from Sea Water

University of California, Berkeley, chemists have discovered a way to simplify the removal of toxic metals, like mercury and boron, during desalination to produce clean water, while at the same time potentially capturing valuable metals, such as gold.

Desalination — the removal of salt — is only one step in the process of producing drinkable water, or water for agriculture or industry, from ocean or waste water. Either before or after the removal of salt, the water often has to be treated to remove boron, which is toxic to plants, and heavy metals like arsenic and mercury, which are toxic to humans. Often, the process leaves behind a toxic brine that can be difficult to dispose of.

The new technique, which can easily be added to current membrane-based electrodialysis desalination processes, removes nearly 100% of these toxic metals, producing a pure brine along with pure water and isolating the valuable metals for later use or disposal.

A flexible polymer membrane incorporating nanoparticles of PAF selectively absorbs nearly 100% of metals such mercury, copper or iron during desalination, more efficiently producing clean, safe water

Desalination or water treatment plants typically require a long series of high-cost, pre- and post-treatment systems that all the water has to go through, one by one,” said Adam Uliana, a UC Berkeley graduate student who is first author of a paper describing the technology. “But here, we have the ability to do several of these steps all in one, which is a more efficient process. Basically, you could implement it in existing setups.”

The UC Berkeley chemists synthesized flexible polymer membranes, like those currently used in membrane separation processes, but embedded nanoparticles that can be tuned to absorb specific metal ionsgold or uranium ions, for example. The membrane can incorporate a single type of tuned nanoparticle, if the metal is to be recovered, or several different types, each tuned to absorb a different metal or ionic compound, if multiple contaminants need to be removed in one step.

The polymer membrane laced with nanoparticles is very stable in water and at high heat, which is not true of many other types of absorbers, including most metal-organic frameworks (MOFs), when embedded in membranes.


Highly Efficient Grid-scale Electricity Storage at Fifth of Cost

Rows of huge tanks full of chemical solutions storing energy generated from massive solar and wind farms and powering whole cities: It’s a landscape that millennials might very well equate with the new normalBatteries will power this new paradigm, and they won’t necessarily all be lithium-ion batteries. The flow battery is staking a claim in the renewable energy world of the future. Flow batteries are definiively the future of energy storage, or at least an important part of it.

What are flow batteries? They are systems of two connected tanks, both containing electrolyte liquids: one with a positively charged cathode and the other with the negatively charged anode, just like a lithium-ion battery. Electricity passes from one electrolyte liquid to the other via a membrane between the tanks.


Rechargeable like lithium-ion batteries, flow batteries have longer lives because the electric current flowing from tank to tank does not degrade the membrane. True flow batteries are also called redox flow batteries, after the two reactions they utilize: reduction, or a gain of electrons, and oxidation, or loss of electrons from electrolyte liquid to electrolyte liquid.

Now researchers in WMG at the University of Warwick, in collaboration with Imperial College London, have found a way to enhance hybrid flow batteries and their commercial use. The new approach can store electricity in these batteries for very long durations for about a fifth the price of current technologies, with minimal location restraints and zero emissions.

The scientists enhanced three hybrid flow cells using nitrogen doped graphene (exposed to nitrogen plasma) in a binder-free electrophoresis technique (EPD). Wind and solar power are increasingly popular sources for renewable energy. Unfortunately, intermittency issues keep them from connecting widely to the National grid. One potential solution to this problem involves in the deployment of long-duration battery technology, such as the redox flow battery. Despite its great promise the current costs of this system are a key determining factor to real-world adoption. An affordable grid battery should cost £75/kWh, according to the US Department of Energy. Lithium-ion batteries, which lead the charge for grid storage, cost about £130/kWh. The hybrid flow battery’s total chemical cost is about 1/30th the cost of competing batteries, such as lithium-ion systems. Scaled-up technologies may be used to store electricity from wind or solar power, for multiple days to entire seasons, for about £15 to £20 per kilowatt hour.

Bionic Eye With Better Vision Than Humans

The world’s first 3D artificial eyeball — capable of outperforming the human eye in some ways — may help droves of people who are partially or fully blind in as little as five years, according to experts.

Researchers from Hong Kong University of Science and Technology have devised an electrochemical eye whose structure and performance mimic those of the ones humans are born with.

The device design has a high degree of structural similarity to a human eye with the potential to achieve high imaging resolution when individual nanowires are electrically addressed,” researchers of Hong Kong University of Science and Technology wrote in a paper published in the journal Nature.

The device converts images through tiny sensors that mirror the lightdetecting photoreceptor cells in a human eyeThe Sun reported. Those sensors reside within a membrane made of aluminum and tungsten which is shaped into a half sphere for the purpose of mimicking a human retina.


How To Bring Fresh Water To Remote Communities

Researchers at the University of Bath (UK) have developed a revolutionary desalination process that has the potential to be operated in mobile, solar-powered units. The process is low cost, low energy and low maintenance, and has the potential to provide safe water to communities in remote and disaster-struck areas where fresh water is in short supply.

Developed by the university’s Water Innovation and Research Centre in partnership with Indonesia’s Bogor Agricultural University and the University of Johannesburg, the prototype desalination unit is a 3D-printed system with two internal chambers designed to extract and/or accumulate salt. When power is applied, salt cations (positively charged ions) and salt anions (negatively charged ions) flow between chambers through arrays of micro-holes in a thin synthetic membrane. The flow can only happen in one direction thanks to a mechanism that has parallels in mobile-phone technology. As a result of this one-way flow, salt is pumped out of seawater. This contrasts with the classical desalination process, where water rather than salt is pumped through a membrane.

Desalination, which turns seawater into fresh water, has become an essential process for providing drinking and irrigation water where freshwater is scarce. Traditionally, it has been an energy-intensive process carried out in large industrial plants.


There are times when it would be enormously beneficial to install small, solar-powered desalination units to service a small number of households. Large industrial water plants are essential to 21st Century living, but they are of no help when you’re living in a remote location where drinking water is scarce, or where there is a coastal catastrophe that wipes out the fresh water supply,” said Professor Frank Marken from the Department of Chemistry

The Bath desalination system is based on ‘ionics’, where a cationic diode (a negatively charged, semi-permeable membrane studded with microscopic pores) is combined with an anionic resistor (a device that only allows the flow of negative ions when power is applied).

This amounts to a whole new process for removing salt from water,”explained Prof Marken. “We are the first people to use tiny micron-sized diodes in a desalination prototype.

He added: “This is a low-energy system with no moving parts. Other systems use enormous pressures to push the water through nano-pores, but we only remove the salts. Most intriguingly, the external pumps and switches can be replaced by microscopic processes inside the membrane – a little bit like biological membranes work.”


How To Create Electricity From Heat

A University of Maryland-led team of researchers has created a heat-to-electricity device that runs on ions and which could someday harness the body’s heat to provide energy.

Led by UMD researchers Liangbing Hu, Robert Briber and Tian Li of the department of materials science, and Siddhartha Das of mechanical engineering, the team transformed a piece of wood into a flexible membrane that generates energy from the same type of electric current (ions) that the human body runs on. This energy is generated using charged channel walls and other unique properties of the wood’s natural nanostructures. With this new wood-based technology, they can use a small temperature differential to efficiently generate ionic voltage, as demonstrated in a paper published in the journal Nature Materials.

If you’ve ever been outside during a lightning storm, you’ve seen that generating charge between two very different temperatures is easy. But for small temperature differences, it is more difficult. However, the team says they have succesfully tackled this challenge.  Hu said they now have “demonstrated their proof-of-concept device, to harvest low-grade heat using nanoionic behavior of processed wood nanostructures”.

Trees grow channels that move water between the roots and the leaves. These are made up of fractally-smaller channels, and at the level of a single cell, channels just nanometers or less across. The team has harnessed these channels to regulate ions.

The researchers used basswood, which is a fast-growing tree with low environmental impact. They treated the wood and removed two components lignin, that makes the wood brown and adds strength, and hemicellulose, which winds around the layers of cells binding them together. This gives the remaining cellulose its signature flexibility.  This process also converts the structure of the cellulose from type I to type II which is a key to enhancing ion conductivity.

A membrane, made of a thin slice of wood, was bordered by platinum electrodes, with sodium-based electrolyte infiltrated into the cellulose. The regulate the ion flow inside the tiny channels and generate electrical signal. “The charged channel walls can establish an electrical field that appears on the nanofibers and thus help effectively regulate ion movement under a thermal gradient,” said Tian Li, first author of the paper.


Portable Machine Harvests Water From Air

Driven by the scarcity of supply, climate change and ground watershed depletion, scientists present a design for a first of its kind portable harvester that mines freshwater from the atmosphere. For thousands of years, people in the Middle East and South America have extracted water from the air to help sustain their populations. Researchers and students from the University of Akron drew inspiration from those examples to develop a lightweight, battery-powered freshwater harvester that could someday take as much as 10 gallons (37,8 liters) per hour from the air, even in arid locations.

I was visiting China, which has a freshwater scarcity problem. There’s investment in wastewater treatment, but I thought that effort alone was inadequate,University of Akron professor Shing-Chung (Josh) Wong said.

Instead of relying on treated wastewater, Wong explained, it might be more prudent to develop a new type of water harvester that takes advantage of abundant water particles in the atmosphere. Freshwater makes up less than 3 percent of the earth’s water sources, and three quarters of that is locked up as ice in the north and south poles. Most water sustainability research is directed toward water supply, purification, wastewater treatment and desalination. Little attention has been paid to water harvesting from atmospheric particles.

Harvesting water from the air has a long history. Thousands of years ago, the Incas of the Andean region collected dew and channeled it into cisterns. More recently, some research groups have been developing massive mist and fog catchers in the Andean mountains and in Africa. Wong’s harvester is directed towards the most abundant atmospheric water sources and uses ground-breaking nanotechnology. If successful, it will produce an agile, lightweight, portable, freshwater harvester powered by a lithium-ion battery.

By experimenting with different combinations of polymers that were hydrophilic — which attracts water — and hydrophobic — which discharges water, the team concluded that a water harvesting system could indeed be fabricated using nanofiber technology. Unlike existing methods, Wong’s harvester could work in arid desert environments because of the membrane’s high surface-area-to-volume ratio. It also would have a minimal energy requirement. “We could confidently say that, with recent advances in lithium-ion batteries, we could eventually develop a smaller, backpack-sized device,” Wong said.