The implant is a flexible polymer electrode and in a recent study was placed in the proverbial three blind mice, (the actual number was seven, three blind males and four females). After a year, the implant has shown that it can deliver electronic vision to the visual cortex. The results have been published in the Journal of Advanced Healthcare Materials. If they can be replicated in humans in the future, this neural implant which is no bigger than a single neuron when combined with others could restore sight to blind people.

Maria Asplund is a Professor of Bioelectronics at Chalmers. She notes that a single implant begins to eliminate the darkness. Multiples could bring back close to normal sight. The more implants, the better the image. But putting more into the brain could be overwhelming. Not so states Professor Asplund.

Each implanted device is called a thread for a good reason. They are very tiny and contain multiple aligned electrodes. An electrode the size of a neuron sounds impossible, yet advancements in nanofabrication have made it a reality.

States Professor Asplund, “Miniaturization of vision implant components is essential. Especially the electrodes, as they need to be small enough to be able to resolve stimulation to large numbers of spots in the brain visual areas.” 

Implanting several threads would put thousands of electrodes in contact with the brain’s visual areas. To restore full vision, you would probably need to implant hundreds in the visual cortex of the brain. Each is less than 15 micrometres or 15 millionths of a metre.

The study has demonstrated these implants are proving to be remarkably stable over a year and have stood up to billions of electrical pulses sent to them to train the visual cortex of the mice to see the images produced. Each of the pulses has been between 2 and 20 microamperes, far below the maximum threshold the electrodes can withstand. The natural immune response to their presence has been minimal producing little damage to the surrounding brain tissue.

The Chalmers and NIN invention improves on work previously demonstrated in 2018 by an implant invented by researchers at the John A. Moran Eye Center at the University of Utah in conjunction with Miguel Hernandez University in Spain. A penny-sized visual prosthesis made from silicon was implanted in the brain of a 58-year-old woman named Berna Gomez. She had lost her sight 16 years earlier after developing toxic optic neuropathy, a condition that destroyed her optic nerves. The Utah device allowed her to see two-dimensional shapes and letters but unfortunately degraded over time because it stimulated an immune response. Its size also made it too large to be practical for full-sight restoration.

The threadlike design of the Chalmers invention allows a large number of electrodes to be implanted within the visual cortex without overwhelming the brain. It has produced little reaction from the body’s autoimmune response. It represents a design proof-of-principle.

For more than 1 million Americans and close to 50,000 Canadians, let alone the many tens of millions on the rest of the planet, this technology could give them sight or restore it if once lost.

Testing in human hosts is still in the offing. Should human clinical trials succeed, this invention could become a promising prosthetic therapy for restoring vision through electronic stimulation of the visual cortex.

• Water – over 9 billion cubic metres annually.
• Concrete – over 4.16 billion cubic metres annually.

No other Earth material usage matches these two. But unlike water which is essential to life on Earth, concrete materials have a Jekyll and Hyde relationship with us. The Jekyll side of concrete is its use in almost everything humans build on the planet. Its Hyde side is the amount of greenhouse gas emissions created when we produce it.

Today’s process of producing concrete begins with the mining of raw limestone and clay which is then crushed, mixed with other materials and then fed into kilns to be heated to 1,450 Celsius (2,640 Fahrenheit) degrees. The output yields clinkers, a greyish chunky output that is cooled, ground, and mixed with additional limestone and gypsum to make the raw cement that goes into concrete. The industrial process produces lots of carbon dioxide (CO2) amounting to 8% of total greenhouse gasses emitted into the atmosphere today.

For those who raise the issue of water vapour being a far more visible greenhouse gas, it should be noted that Earth’s atmosphere long ago accommodated the water cycle. What the atmosphere, in accommodating today’s industrial emissions, is doing is heating up with concrete representing number four in the list of biggest greenhouse gas sources, trailing only coal, oil, and natural gas.

Concrete producers are well aware of the Paris Climate Agreement and the goal of countries and the industry to achieve net-zero emissions by 2050 and to be in negative emissions after that to draw down on existing CO2 in the atmosphere. What that means is a dramatic change in every aspect of the production process. Retrofitting older cement plants to burn blue and green hydrogen as fuel for kilns is one solution. Capturing CO2 is another.

A company based in Canada has made CO2 part of its end product. CarbonCure Technologies’ recipe for concrete turns its finished concrete blocks and pavers into a carbon sink. Another company, HeidelbergCement, a German company recently announced plans to build the first CO2-neutral cement plant in the world to be located in Sweden and operational by 2030.

The alternative to these types of solutions is for architects and builders to stop using concrete materials which would be better for the atmosphere, but for the industry, disastrous.

But what about all those concrete buildings and structures already in existence? Is there something that they can do to contribute to achieving a low-carbon future? Researchers may have come up with just the right idea: to turn concrete into rechargeable batteries.

Using concrete to store electricity is an idea that is gaining ground and although the material is far less efficient in storing electricity than traditional chemical and solid-state batteries, its abundance makes it a very attractive option. What would be great is to be able to turn existing concrete building inventories into battery storage for renewable energy producers. Imagine a building with solar arrays pumping out electricity and its concrete walls acting as battery backup when the sun is no longer shining.

We are not there yet, but Emma Qingnan Zhang and Lu-Ping Tang, of the Division of Building Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, in Gothenburg, Sweden, have a cement-based battery with energy densities of 7 Watt-hours per cubic metre. To use cement as a battery the researchers have incorporated anodes of iron and zinc, and cathodes of nickel-based oxides along with carbon fibres into the mix. And although their battery doesn’t generate a lot of power when compared to chemical and solid-state ones, with concrete as a primary construction material, turning buildings into storage batteries while serving as living accommodation would be a game-changer.

To get the exact shape right the researchers used bright-field microscopy combined with nonlinear microscopy to create exact images of the targeted area within a simulated body. The iPSCs were encapsulated within a number of different bioinks to test the efficacy of each and determine which was most suitable for cartilage regeneration. After three weeks chondrocyte growth was indicated. The researchers noted that increasing the iPSC volume would likely speed up the proliferation of chondrocytes and the restoration of the body’s natural cartilage.

iPSCs don’t necessarily form chondrocytes. Being undifferentiated stem cells means that they could turn into almost any body tissue. So one of the issues the researchers had to address was ensuring that existing chondrocytes were at the locality where the bioink was introduced. That stimulated the iPSCs to turn into chondrocytes.

The researchers acknowledge that we still have a considerable way to go before we get to the point where it will be routine not to have knee or hip replacement surgery, but rather infuse stem cells into an affected joint to regrow lost cartilage to meet exact physical requirements. For me, the advancement in this technology cannot come soon enough to help me regenerate my left knee, and maybe even give my right one some fine tuning.

This latest research is being done at the Chalmers University of Technology, Gothenburg, Sweden, the Department of Clinical Chemistry and Transfusion Medicine, University of Gothenburg, and the Kungsbacka Hospital, in Kungsbacka, Sweden.