Your Future Smartphone May Detect Problems in Your Water
In 2014, the city of Flint, Michigan switched the residents' water supply to the Flint river, citing cheaper costs. However, due to improper filtering, lead contaminated this water, and according to the Associated Press, many of the city's residents soon reported health issues like hair loss and rashes. In 2015, a report found that children there had high levels of lead in their blood. The National Resource Defense Council recently discovered there could still be as many as twelve million lead pipes carrying water to homes across the U.S.
What if Flint residents and others in afflicted areas could simply flick water onto their phone screens and an app would tell them if they were about to drink contaminated water? This is what researchers at the University of Cambridge are working on to prevent catastrophes like what occurred in Flint, and to prepare for an uncertain future of scarcer resources.
Underneath the tough glass of our phone screen lies a transparent layer of electrodes. Because our bodies hold an electric charge, when our finger touches the screen, it disrupts the electric field created among the electrodes. This is how the screen can sense where a touch occurs. Cambridge scientists used this same idea to explore whether the screen could detect charges in water, too.Metals like arsenic and lead can appear in water in the form of ions, which are charged particles. When the ionic solution is placed on the screen's surface, the electrodes sense that charge like how they sense our finger.
Imagine a new generation of smartphones with a designated area of the screen responsible for detecting contamination—this is one of the possible futures the researchers propose.
The experiment measured charges in various electrolyte solutions on a touchscreen. The researchers found that a thin polymer layer between the electrodes and the sample solution helped pick up the charges.
"How can we get really close to the touch electrodes, and be better than a phone screen?" Horstmann, the lead scientist on the study, asked himself while designing the protective coating. "We found that when we put electrolytes directly on the electrodes, they were too close, even short-circuiting," he said. When they placed the polymer layer on top the electrodes, however, this short-circuiting did not occur. Horstmann speaks of the polymer layer as one of the key findings of the paper, as it allowed for optimum conductivity. The coating they designed was much thinner than what you'd see with a typical smartphone touchscreen, but because it's already so similar, he feels optimistic about the technology's practical applications in the real world.
While the Cambridge scientists were using touchscreens to measure water contamination, Dr. Baojun Wang, a synthetic biologist at the University of Edinburgh, along with his team, created a way to measure arsenic contamination in Bangladesh groundwater samples using what is called a cell-based biosensor.These biosensors use cornerstones of cellular activity like transcription and promoter sequences to detect the presence of metal ions in water. A promoter can be thought of as a "flag" that tells certain molecules where to begin copying genetic code. By hijacking this aspect of the cell's machinery and increasing the cell's sensing and signal processing ability, they were able to amplify the signal to detect tiny amounts of arsenic in the groundwater samples. All this was conducted in a 384-well plate, each well smaller than a pencil eraser.
They placed arsenic sensors with different sensitivities across part of the plate so it resembled a volume bar of increasing levels of arsenic, similar to diagnostics on a Fitbit or glucose monitor. The whole device is about the size of an iPhone, and can be scaled down to a much smaller size.
Dr. Wang says cell-based biosensors are bringing sensing technology closer to field applications, because their machinery uses inherent cellular activity. This makes them ideal for low-resource communities, and he expects his device to be affordable, portable, and easily stored for widespread use in households.
"It hasn't worked on actual phones yet, but I don't see any reason why it can't be an app," says Horstmann of their technology.Imagine a new generation of smartphones with a designated area of the screen responsible for detecting contamination—this is one of the possible futures the researchers propose. But industry collaborations will be crucial to making their advancements practical. The scientists anticipate that without collaborative efforts from the business sector, the public might have to wait ten years until this becomes something all our smartphones are capable of—but with the right partners, "it could go really quickly," says Dr. Elizabeth Hall, one of the authors on the touchscreen water contamination study.
"That's where the science ends and the business begins," Dr. Hall says. "There is a lot of interest coming through as a result of this paper. I think the people who make the investments and decisions are seeing that there might be something useful here."
As for Flint, according to The Detroit News, the city has entered the final stages in removing lead pipe infrastructure. It's difficult to imagine how many residents might fare better today if they'd had the technology that scientists are now creating.
Of all its tragedy, COVID-19 has increased demand for at-home testing methods, which has carried over to non-COVID-19-related devices. Various testing efforts are now in the public eye.
"I like that the public is watching these directions," says Horstmann. "I think there's a long way to go still, but it's exciting."
Story by Freethink
Try burning an iron metal ingot and you’ll have to wait a long time — but grind it into a powder and it will readily burst into flames. That’s how sparklers work: metal dust burning in a beautiful display of light and heat. But could we burn iron for more than fun? Could this simple material become a cheap, clean, carbon-free fuel?
In new experiments — conducted on rockets, in microgravity — Canadian and Dutch researchers are looking at ways of boosting the efficiency of burning iron, with a view to turning this abundant material — the fourth most common in the Earth’s crust, about about 5% of its mass — into an alternative energy source.
Iron as a fuel
Iron is abundantly available and cheap. More importantly, the byproduct of burning iron is rust (iron oxide), a solid material that is easy to collect and recycle. Neither burning iron nor converting its oxide back produces any carbon in the process.
Iron oxide is potentially renewable by reacting with electricity or hydrogen to become iron again.
Iron has a high energy density: it requires almost the same volume as gasoline to produce the same amount of energy. However, iron has poor specific energy: it’s a lot heavier than gas to produce the same amount of energy. (Think of picking up a jug of gasoline, and then imagine trying to pick up a similar sized chunk of iron.) Therefore, its weight is prohibitive for many applications. Burning iron to run a car isn’t very practical if the iron fuel weighs as much as the car itself.
In its powdered form, however, iron offers more promise as a high-density energy carrier or storage system. Iron-burning furnaces could provide direct heat for industry, home heating, or to generate electricity.
Plus, iron oxide is potentially renewable by reacting with electricity or hydrogen to become iron again (as long as you’ve got a source of clean electricity or green hydrogen). When there’s excess electricity available from renewables like solar and wind, for example, rust could be converted back into iron powder, and then burned on demand to release that energy again.
However, these methods of recycling rust are very energy intensive and inefficient, currently, so improvements to the efficiency of burning iron itself may be crucial to making such a circular system viable.
The science of discrete burning
Powdered particles have a high surface area to volume ratio, which means it is easier to ignite them. This is true for metals as well.
Under the right circumstances, powdered iron can burn in a manner known as discrete burning. In its most ideal form, the flame completely consumes one particle before the heat radiating from it combusts other particles in its vicinity. By studying this process, researchers can better understand and model how iron combusts, allowing them to design better iron-burning furnaces.
Discrete burning is difficult to achieve on Earth. Perfect discrete burning requires a specific particle density and oxygen concentration. When the particles are too close and compacted, the fire jumps to neighboring particles before fully consuming a particle, resulting in a more chaotic and less controlled burn.
Presently, the rate at which powdered iron particles burn or how they release heat in different conditions is poorly understood. This hinders the development of technologies to efficiently utilize iron as a large-scale fuel.
Burning metal in microgravity
In April, the European Space Agency (ESA) launched a suborbital “sounding” rocket, carrying three experimental setups. As the rocket traced its parabolic trajectory through the atmosphere, the experiments got a few minutes in free fall, simulating microgravity.
One of the experiments on this mission studied how iron powder burns in the absence of gravity.
In microgravity, particles float in a more uniformly distributed cloud. This allows researchers to model the flow of iron particles and how a flame propagates through a cloud of iron particles in different oxygen concentrations.
Existing fossil fuel power plants could potentially be retrofitted to run on iron fuel.
Insights into how flames propagate through iron powder under different conditions could help design much more efficient iron-burning furnaces.
Clean and carbon-free energy on Earth
Various businesses are looking at ways to incorporate iron fuels into their processes. In particular, it could serve as a cleaner way to supply industrial heat by burning iron to heat water.
For example, Dutch brewery Swinkels Family Brewers, in collaboration with the Eindhoven University of Technology, switched to iron fuel as the heat source to power its brewing process, accounting for 15 million glasses of beer annually. Dutch startup RIFT is running proof-of-concept iron fuel power plants in Helmond and Arnhem.
As researchers continue to improve the efficiency of burning iron, its applicability will extend to other use cases as well. But is the infrastructure in place for this transition?
Often, the transition to new energy sources is slowed by the need to create new infrastructure to utilize them. Fortunately, this isn’t the case with switching from fossil fuels to iron. Since the ideal temperature to burn iron is similar to that for hydrocarbons, existing fossil fuel power plants could potentially be retrofitted to run on iron fuel.
Tom Oxley is building what he calls a “natural highway into the brain” that lets people use their minds to control their phones and computers. The device, called the Stentrode, could improve the lives of hundreds of thousands of people living with spinal cord paralysis, ALS and other neurodegenerative diseases.
Leaps.org talked with Dr. Oxley for today’s podcast. A fascinating thing about the Stentrode is that it works very differently from other “brain computer interfaces” you may be familiar with, like Elon Musk’s Neuralink. Some BCIs are implanted by surgeons directly into a person’s brain, but the Stentrode is much less invasive. Dr. Oxley’s company, Synchron, opts for a “natural” approach, using stents in blood vessels to access the brain. This offers some major advantages to the handful of people who’ve already started to use the Stentrode.
The audio improves about 10 minutes into the episode. (There was a minor headset issue early on, but everything is audible throughout.) Dr. Oxley’s work creates game-changing opportunities for patients desperate for new options. His take on where we're headed with BCIs is must listening for anyone who cares about the future of health and technology.
In our conversation, Dr. Oxley talks about “Bluetooth brain”; the critical role of AI in the present and future of BCIs; how BCIs compare to voice command technology; regulatory frameworks for revolutionary technologies; specific people with paralysis who’ve been able to regain some independence thanks to the Stentrode; what it means to be a neurointerventionist; how to scale BCIs for more people to use them; the risks of BCIs malfunctioning; organic implants; and how BCIs help us understand the brain, among other topics.
Dr. Oxley received his PhD in neuro engineering from the University of Melbourne in Australia. He is the founding CEO of Synchron and an associate professor and the head of the vascular bionics laboratory at the University of Melbourne. He’s also a clinical instructor in the Deepartment of Neurosurgery at Mount Sinai Hospital. Dr. Oxley has completed more than 1,600 endovascular neurosurgical procedures on patients, including people with aneurysms and strokes, and has authored over 100 peer reviewed articles.
Synchron website - https://synchron.com/
Assessment of Safety of a Fully Implanted Endovascular Brain-Computer Interface for Severe Paralysis in 4 Patients (paper co-authored by Tom Oxley) - https://jamanetwork.com/journals/jamaneurology/art...
More research related to Synchron's work - https://synchron.com/research
Tom Oxley on LinkedIn - https://www.linkedin.com/in/tomoxl
Tom Oxley on Twitter - https://twitter.com/tomoxl?lang=en
Tom Oxley website - https://tomoxl.com/
Novel brain implant helps paralyzed woman speak using digital avatar - https://engineering.berkeley.edu/news/2023/08/novel-brain-implant-helps-paralyzed-woman-speak-using-a-digital-avatar/
Edward Chang lab - https://changlab.ucsf.edu/
BCIs convert brain activity into text at 62 words per minute - https://med.stanford.edu/neurosurgery/news/2023/he...
Leaps.org: The Mind-Blowing Promise of Neural Implants - https://leaps.org/the-mind-blowing-promise-of-neural-implants/