Solar Cells with 30-year Lifetimes

A new transparency-friendly solar cell design could marry high efficiencies with 30-year estimated lifetimes, research led by the University of Michigan has shown. It may pave the way for windows that also provide solar power.

Solar energy is about the cheapest form of energy that mankind has ever produced since the industrial revolution,” said Stephen Forrest, Professor of Electrical Engineering, who led the research. “With these devices used on windows, your building becomes a power plant.”

While silicon remains king for solar panel efficiency, it isn’t transparent. For window-friendly solar panels, researchers have been exploring organic—or carbon-basedmaterials. The challenge for Forrest’s team was how to prevent very efficient organic light-converting materials from degrading quickly during use.

The strength and the weakness of these materials lie in the molecules that transfer the photogenerated electrons to the electrodes, the entrance points to the circuit that either uses or stores the solar power. These materials are known generally as “non-fullerene acceptors” to set them apart from the more robust but less efficient “fullerene acceptors” made of nanoscale carbon mesh. Solar cells made with non-fullerene acceptors that incorporate sulfur can achieve silicon-rivaling efficiencies of 18%, but they do not last as long.

The team, including researchers at North Carolina State University and Tianjin University and Zhejiang University in China, set out to change that. In their experiments, they showed that without protecting the sunlight-converting material, the efficiency fell to less than 40% of its initial value within 12 weeks under the equivalent of 1 sun’s illumination.

Non-fullerene acceptors cause very high efficiency, but contain weak bonds that easily dissociate under high energy photons, especially the UV [ultraviolet] photons common in sunlight,” said Yongxi Li, U-M assistant research scientist in electrical engineering and computer science and first author of the paper in Nature Communications.

Source: https://news.umich.edu/

Brain Implants Imminent

It’s inevitable that we’ll see brain implants become a common piece of technology — first for those who suffer from certain neurological disorders like epilepsy, then later on as an enhancement for the average person looking for a cognitive boost. Despite growing research and development in the field of brain-computer interfaces (BCIs), there has been little progress when it comes to the ethics of this technology.

Two new papers have been published by researchers with North Carolina State University addressing the ethical matters around BCI technology, including external devices that aren’t implanted and internal devices that are implanted in the brain. The researchers pay particular focus on implanted BCIs and such technologies intended for cognitive enhancement.

Put simply, BCI devices are designed to take brain signals and translate them into data for a computer to utilize. Perhaps the best example of such technology comes from Elon Musk’s Neuralink, which recently gave a demonstration of a brain implant involving pigs. Musk presented the technology as promising for people suffering from neurological conditions, among other things.

The invasive devices are more efficient, since they can read signals directly from the brain. However, they also raise more ethical concerns. For example, invasive BCI technologies carry more associated risks such as surgery, infection, and glial scarring – and invasive BCI devices would be more difficult to replace as technology improves.” said Veljko Dubljević, a co-author on both of the new papers, pointing out the particularly tricky issue of implants.

Among other things, the papers note that there are two areas, in particular, that should get priority when it comes to exploring ethical considerations: the psychological and physical effects of brain-computer interfaces. Multiple issues are presented, including the potential long-term effects of these devices, whether it is ethical to use animals to test invasive technologies, and what kind of psychological effects may manifest related to various BCI technologies.

The researchers present one example of potential unwanted psychological outcomes, noting a study in which people with epilepsy were given an advanced warning of seizures via an invasive BCI — and some of those patients went on to develop ‘radical psychological distress’ as a result. The researchers also explore the potential future use of BCIs for enhancing cognition, a technological future that would expand beyond the current trend of using ‘smart drugs.’ If someone with an enhancing implant takes a test, are the results ‘authenticas they would be from someone who doesn’t have a BCI?

Source: https://www.slashgear.com/

Nanospheres Dissolve Clots In A Few Minutes

Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have developed a drug-delivery system that allows rapid response to heart attacks without surgical intervention. In laboratory and animal testing, the system proved to be effective at dissolving clots, limiting long-term scarring to heart tissue and preserving more of the heart’s normal function.

Our approach would allow health-care providers to begin treating heart attacks before a patient reaches a surgical suite, hopefully improving patient outcomes,” says Ashley Brown, corresponding author of a paper on the work and an assistant professor in the Joint Biomedical Engineering Program (BME) at NC State and UNC. “And because we are able to target the blockage, we are able to use powerful drugs that may pose threats to other parts of the body; the targeting reduces the risk of unintended harms.”

Heart attacks, or myocardial infarctions, occur when a thrombus – or clotblocks a blood vessel in the heart. In order to treat heart attacks, doctors often perform surgery to introduce a catheter to the blood vessel, allowing them to physically break up or remove the thrombus. But not all patients have quick access to surgical care. And more damage can occur even after the blockage has been removed. That’s because the return of fresh blood to tissues that had been blocked off can cause damage of its own, called reperfusion injury. Reperfusion injury can cause scarring, stiffening cardiac tissue and limiting the heart’s normal functionality.

To address these problems, researchers have developed a solution that relies on porous nanogel spheres, about 250 nanometers in diameter, which target a thrombus and deliver a cocktail of two drugs: tPA and Y-27632.

In in vitro testing, the researchers found that the targeted tPA/Y-27632 cocktail dissolved clots in a matter of minutes. While this has yet to be tested in trials, it may work more quickly than surgical interventions, which require time to prep the patient and get the catheter in place. In tests using laboratory rats, the researchers also found that their technique limited scarring and preserved heart function after heart attack better than targeted tPA or Y-27632 by themselves – and far better than a control group in which animals received neither drug.

The paper was recently published in the journal ACS Nano. Trials on larger animals are now being planned.

Source: https://news.ncsu.edu/