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."
This man spent over 70 years in an iron lung. What he was able to accomplish is amazing.
It’s a sight we don’t normally see these days: A man lying prone in a big, metal tube with his head sticking out of one end. But it wasn’t so long ago that this sight was unfortunately much more common.
In the first half of the 20th century, tens of thousands of people each year were infected by polio—a highly contagious virus that attacks nerves in the spinal cord and brainstem. Many people survived polio, but a small percentage of people who did were left permanently paralyzed from the virus, requiring support to help them breathe. This support, known as an “iron lung,” manually pulled oxygen in and out of a person’s lungs by changing the pressure inside the machine.
Paul Alexander was one of several thousand who were infected and paralyzed by polio in 1952. That year, a polio epidemic swept the United States, forcing businesses to close and polio wards in hospitals all over the country to fill up with sick children. When Paul caught polio in the summer of 1952, doctors urged his parents to let him rest and recover at home, since the hospital in his home suburb of Dallas, Texas was already overrun with polio patients.
Paul rested in bed for a few days with aching limbs and a fever. But his condition quickly got worse. Within a week, Paul could no longer speak or swallow, and his parents rushed him to the local hospital where the doctors performed an emergency procedure to help him breathe. Paul woke from the surgery three days later, and found himself unable to move and lying inside an iron lung in the polio ward, surrounded by rows of other paralyzed children.
Hospitals were commonly filled with polio patients who had been paralyzed by the virus before a vaccine became widely available in 1955. Associated Press
Paul struggled inside the polio ward for the next 18 months, bored and restless and needing to hold his breath when the nurses opened the iron lung to help him bathe. The doctors on the ward frequently told his parents that Paul was going to die.But against all odds, Paul lived. And with help from a physical therapist, Paul was able to thrive—sometimes for small periods outside the iron lung.
The way Paul did this was to practice glossopharyngeal breathing (or as Paul called it, “frog breathing”), where he would trap air in his mouth and force it down his throat and into his lungs by flattening his tongue. This breathing technique, taught to him by his physical therapist, would allow Paul to leave the iron lung for increasing periods of time.
With help from his iron lung (and for small periods of time without it), Paul managed to live a full, happy, and sometimes record-breaking life. At 21, Paul became the first person in Dallas, Texas to graduate high school without attending class in person, owing his success to memorization rather than taking notes. After high school, Paul received a scholarship to Southern Methodist University and pursued his dream of becoming a trial lawyer and successfully represented clients in court.
Paul Alexander, pictured here in his early 20s, mastered a type of breathing technique that allowed him to spend short amounts of time outside his iron lung. Paul Alexander
Paul practiced law in North Texas for more than 30 years, using a modified wheelchair that held his body upright. During his career, Paul even represented members of the biker gang Hells Angels—and became so close with them he was named an honorary member.Throughout his long life, Paul was also able to fly on a plane, visit the beach, adopt a dog, fall in love, and write a memoir using a plastic stick to tap out a draft on a keyboard. In recent years, Paul joined TikTok and became a viral sensation with more than 330,000 followers. In one of his first videos, Paul advocated for vaccination and warned against another polio epidemic.
Paul was reportedly hospitalized with COVID-19 at the end of February and died on March 11th, 2024. He currently holds the Guiness World Record for longest survival inside an iron lung—71 years.
Polio thankfully no longer circulates in the United States, or in most of the world, thanks to vaccines. But Paul continues to serve as a reminder of the importance of vaccination—and the power of the human spirit.
““I’ve got some big dreams. I’m not going to accept from anybody their limitations,” he said in a 2022 interview with CNN. “My life is incredible.”
When doctors couldn’t stop her daughter’s seizures, this mom earned a PhD and found a treatment herself.
Twenty-eight years ago, Tracy Dixon-Salazaar woke to the sound of her daughter, two-year-old Savannah, in the midst of a medical emergency.
“I entered [Savannah’s room] to see her tiny little body jerking about violently in her bed,” Tracy said in an interview. “I thought she was choking.” When she and her husband frantically called 911, the paramedic told them it was likely that Savannah had had a seizure—a term neither Tracy nor her husband had ever heard before.
Over the next several years, Savannah’s seizures continued and worsened. By age five Savannah was having seizures dozens of times each day, and her parents noticed significant developmental delays. Savannah was unable to use the restroom and functioned more like a toddler than a five-year-old.
Doctors were mystified: Tracy and her husband had no family history of seizures, and there was no event—such as an injury or infection—that could have caused them. Doctors were also confused as to why Savannah’s seizures were happening so frequently despite trying different seizure medications.
Doctors eventually diagnosed Savannah with Lennox-Gaustaut Syndrome, or LGS, an epilepsy disorder with no cure and a poor prognosis. People with LGS are often resistant to several kinds of anti-seizure medications, and often suffer from developmental delays and behavioral problems. People with LGS also have a higher chance of injury as well as a higher chance of sudden unexpected death (SUDEP) due to the frequent seizures. In about 70 percent of cases, LGS has an identifiable cause such as a brain injury or genetic syndrome. In about 30 percent of cases, however, the cause is unknown.
Watching her daughter struggle through repeated seizures was devastating to Tracy and the rest of the family.
“This disease, it comes into your life. It’s uninvited. It’s unannounced and it takes over every aspect of your daily life,” said Tracy in an interview with Today.com. “Plus it’s attacking the thing that is most precious to you—your kid.”
Desperate to find some answers, Tracy began combing the medical literature for information about epilepsy and LGS. She enrolled in college courses to better understand the papers she was reading.
“Ironically, I thought I needed to go to college to take English classes to understand these papers—but soon learned it wasn’t English classes I needed, It was science,” Tracy said. When she took her first college science course, Tracy says, she “fell in love with the subject.”
Tracy was now a caregiver to Savannah, who continued to have hundreds of seizures a month, as well as a full-time student, studying late into the night and while her kids were at school, using classwork as “an outlet for the pain.”
“I couldn’t help my daughter,” Tracy said. “Studying was something I could do.”
Twelve years later, Tracy had earned a PhD in neurobiology.
After her post-doctoral training, Tracy started working at a lab that explored the genetics of epilepsy. Savannah’s doctors hadn’t found a genetic cause for her seizures, so Tracy decided to sequence her genome again to check for other abnormalities—and what she found was life-changing.
Tracy discovered that Savannah had a calcium channel mutation, meaning that too much calcium was passing through Savannah’s neural pathways, leading to seizures. The information made sense to Tracy: Anti-seizure medications often leech calcium from a person’s bones. When doctors had prescribed Savannah calcium supplements in the past to counteract these effects, her seizures had gotten worse every time she took the medication. Tracy took her discovery to Savannah’s doctor, who agreed to prescribe her a calcium blocker.
The change in Savannah was almost immediate.
Within two weeks, Savannah’s seizures had decreased by 95 percent. Once on a daily seven-drug regimen, she was soon weaned to just four, and then three. Amazingly, Tracy started to notice changes in Savannah’s personality and development, too.
“She just exploded in her personality and her talking and her walking and her potty training and oh my gosh she is just so sassy,” Tracy said in an interview.
Since starting the calcium blocker eleven years ago, Savannah has continued to make enormous strides. Though still unable to read or write, Savannah enjoys puzzles and social media. She’s “obsessed” with boys, says Tracy. And while Tracy suspects she’ll never be able to live independently, she and her daughter can now share more “normal” moments—something she never anticipated at the start of Savannah’s journey with LGS. While preparing for an event, Savannah helped Tracy get ready.
“We picked out a dress and it was the first time in our lives that we did something normal as a mother and a daughter,” she said. “It was pretty cool.”