Reza Ghodssi, a professor of electrical and computer engineering at the University of Maryland who was not involved in the study. "The battery is one component that takes up most of the space in an ingestible device, so anything that can provide the required power while reducing the size of the capsule is very promising."
Examples of ingestible medical devices include those that detect bleeding, dispense medicines, or stimulate specific tissues or organs.
How does the battery work?
Conventional batteries used in ingestible devices are not only large; they also need to stay sealed to prevent their internal materials from leaking into surrounding tissue and causing damage. The new battery, described Monday (Sept. 21) in the journal Nature Chemical Engineering, is made from materials that gradually dissolve in the acidic gastrointestinal tract and can then be safely absorbed without leaving behind harmful fragments or toxic byproducts.
The battery is built in layers. A magnesium alloy forms the anode (the battery's negative terminal), while the cathode (positive terminal) contains molybdenum trioxide and activated carbon. Between the two sides is a biodegradable electrolyte that allows the battery to generate electric current. These materials have been used in earlier biodegradable battery prototypes for temporary medical and wearable electronics.
The new design adapts them into a thin, porous, paper-like battery using cellulose nanofibrils as a binder, whereas earlier versions used larger binders. "The paper structure improves the battery's strength and control over degradation while still allowing it to produce electricity," study co-author Giovanni Traverso, director of the Laboratory for Translational Engineering at MIT, told Live Science in an email.
To keep the battery from breaking down too quickly in stomach acid, the researchers coated it with beeswax. Some versions also got a layer of candelilla wax — derived from the desert shrub Euphorbia antisyphilitica — for longer protection.
"The wax coating is not simply packaging," Traverso said. "It is a key design element that controls the functional lifetime."
The team made two versions of the battery, including one that was small enough to fit inside a standard gelatin capsule. In lab tests, it produced about 1.77 volts and could store and deliver 2 milliampere-hours per square centimeter, which is enough capacity to power low-power electronics.
A larger version of the battery produced about 1.84 volts and had a maximum capacity of 3.5 milliampere-hours. That could power devices that need a bit more power. However, the battery's capacity is still low, Ghodssi noted. "They need to have an order of magnitude higher capacity for this technology to be even more promising," he said.
Testing the battery inside the body
The researchers placed the battery prototypes inside 3D-printed capsules and administered them to pigs orally using an endoscope — essentially a long tube. Both versions of the battery worked for up to three days, although their voltage and capacity dropped as they gradually degraded. The larger battery's voltage dropped from about 1.8 volts to 1.6 volts after one day and then down to about 1.45 volts by the third day, while the smaller battery fell from 1.7 volts to 1.35 volts over the same period.
A battery-powered RFID tag (shown next to a U.S. quarter) tracked medication intake in pigs and enabled wireless monitoring from 5 feet away. (Image credit: Mehmet Girayhan Say)The team used the batteries to power two types of medical devices inside the pigs. The smaller battery powered a wireless RFID (radio-frequency identification) tag. Similar RFID-based sensors have been tested in people before, but the one used in this study was experimental. Researchers positioned it in the esophagus, where the tag communicated with a receiver up to 5 feet (1.5 meters) away and allowed researchers to detect when the pigs swallowed a medication.
The larger battery powered a swallowable capsule that electrically stimulated the stomach; this increased levels of the hunger-stimulating hormone ghrelin in the blood without causing visible tissue damage at the stimulation site. Gastric electrical stimulation is already used in people with severe gastroparesis, a condition that slows the rate at which the stomach empties; the battery-powered capsule tested in this study is experimental.
"It's quite impressive that the battery can operate in a stable and reliable fashion as the overall device passes through the GI system in a large animal model," said John Rogers, a pioneer in bioelectronics and a materials scientist at Northwestern University who was not involved in the study.
The battery and its biodegradable components broke down, but the electronic circuit board used for the stomach-stimulation experiment did not; instead, the pigs passed it naturally. "Making every part of the device bioresorbable could eliminate the risk of a leftover component becoming lodged in the gastrointestinal tract," Rogers said.
The researchers' biggest remaining challenge is controlling the battery's working lifetime and making its breakdown more predictable, Traverso said.
The researchers also found some variability between the batteries, which they attributed to factors in their construction, including the amount of contact between layers, their electrolyte distribution, and differences in the thickness of the wax coating. The team is now working to standardize manufacturing and adjust the coating so the batteries can be designed to function for specific periods of time, ranging from hours to days.
The team also plans to conduct longer tests under conditions that more closely mimic the human gastrointestinal tract. They are working toward an initial clinical trial of the RFID system that could begin in about two years, Traverso said.
'> Scientists made a paper battery you can swallow to power internal medical devices
Patience is often rewarded with some of the most impressive meteors of the year, partly because the Southern Taurid meteors strike Earth's atmosphere at the relatively leisurely pace of around 17 miles per second (27 kilometers per second), meaning they can be visible longer than most meteors and leave glowing trails.
The Southern Taurids are associated with a trail of rocky debris left in the inner solar system by Comet 2P/Encke, according to NASA, and they form half of the broader Taurid meteor complex. Their companion shower, the Northern Taurids, becomes active later in the fall, creating an extended period when Earth encounters debris associated with the same complex.
Although meteor activity begins this month, you'll have to wait a little longer to see the Southern Taurids at their best. An early increase in activity is expected around Oct. 13-14, with rates of regular shooting stars potentially slightly stronger than usual this year, while the principal peak for fireballs will arrive around the night of Nov. 4-5.
The sky conditions will be ideal for the Southern Taurids, with a moonless night sky on Oct. 13-14 and an 18%-lit waning crescent moon rising in the early morning on Nov. 5, though you will also need a clear night to see any shooting stars or fireballs. However, the rates will be too low for most urbanites to justify a trip to a dark location.
Southern Taurid meteors appear to radiate from the constellation Taurus, which climbs higher as the night progresses, but there's no need to stare directly at it. Meteors can appear anywhere overhead, so a wide, unobstructed view of the sky is more useful. Stargazing binoculars and telescopes will not help you spot meteors — however, they may come in handy for some of fall's other skywatching treats, including some rare planetary appearances.
Because the shower's radiant lies close to the ecliptic (the apparent path of the sun as seen from Earth), the Southern Taurids are observable from both hemispheres. However, Northern Hemisphere observers generally enjoy more favorable viewing conditions.
Don't expect celestial fireworks; the Southern Taurids are a slow burn. But with brilliant fireballs possible, they're worth keeping an eye on whenever you're outside after dark this fall.
'> One of the longest-running meteor showers of the year has begun: How to get the best views of the Southern Taurids A prehistoric gold funeral mask from Java. (Image credit: Yale University Art Museum (CC0 1.0 Universal))QUICK FACTS
Name: Funeral mask
What it is: A gold mask with a humanlike face
Where it is from: Java, Indonesia
When it was made: Between 500 B.C. and A.D. 200
This gold mask was made on the Indonesian island of Java around two millennia ago and was likely used to cover the face of a corpse, possibly with the aim of "confusing" the deceased's spirit so that it did not torment the living.
According to the Yale University Art Gallery, which has the prehistoric artifact in its collection, the mask measures roughly 8.9 by 6.7 inches (22.6 by 17 centimeters) and weighs about 2.1 ounces (60.9 grams). The mask has openings at the mouth, eyes and nostrils, along with slits and slashes representing eyebrows, eyelashes and teeth. A series of holes punched around the edge of the mask suggests that it was once attached to a corpse or funeral statue, archaeologist John Miksic wrote in a book titled "Old Javanese Gold" (Yale University Press, 2011).
To create the mask, an ancient artisan would have procured high-purity gold from the nearby islands of Sumatra or Borneo, hammered the metal into a thin sheet roughly the size and shape of a human face, and then cut the incisions with a chisel, Miksic wrote. Because of the simple technique used to create the mask, Miksic dated the artifact to Java's Preclassic period (500 B.C. to A.D. 200). During this era, prehistoric Javanese people inhumed their dead, before they switched to cremation in the following period. Gold face coverings were therefore most likely part of a prehistoric burial tradition, Miksic noted.
The custom of using gold to cover part or all of the deceased's face has been found in prehistoric India, China and other parts of Southeast Asia, according to Miksic, coinciding with inhumation burials made just before the advent of cremation. But it is unclear whether one culture learned the practice from another or if it was invented independently. Other gold death masks predate the Asian examples, including the famous 3,500-year-old Mask of Agamemnon from Bronze Age Greece.
Scholars have argued about whether Javanese gold death masks were meant to be realistic or idealized versions of the deceased. In a 1990 book on Indonesian traditional masks, archaeologist Wahyono Martowikrido noted that the Javanese mask was unusually naturalistic and was likely created to resemble the deceased.
It is unclear why the ancient Javanese created and used death masks, Miksic wrote, but experts have three main ideas. The ancient Javanese had high regard for the spirits of their ancestors, so they may have used precious gold as the most suitable material for honoring those departed ancestors. Another possibility is that only high-status people merited gold masks, which would have separated the elite from the commoners in the next world.
Miksic also learned from ethnographic accounts of people who lived on eastern Indonesian islands that spirits of the dead could be hostile. To prevent these malevolent spirits from attacking the living, people would turn the corpse around during the funeral procession and even place the corpse's head in a pot to confuse the spirit and make it unable to find its way back. This sort of belief may have led to the use of gold face covers, Miksic wrote.
The gold burial mask is one of the oldest artifacts in a collection of nearly 500 gold objects from Java donated to the Yale University Art Gallery by collectors Hunter and Valerie Thompson in 2007.
For more stunning archaeological discoveries, check out our Astonishing Artifacts archives.
Guldhøj Chair
Kerch Crown
Lady K'abel Stela
Can you put together last week's Astonishing Artifact?
'> Funeral mask: A 2,000-year-old gold face covering designed to confuse the deceased's spirit so it didn't torment the living
Glaciers in Nepal have been shrinking, potentially weakening the mountain slopes. (Image credit: NICHOLAS SHEARMAN via Getty Images)The rock, ice and water that then raced rapidly downstream eroded the riverbanks and collected debris and water along the way.
Carey noted that this disaster was exacerbated by a combination of factors.
"This particular event in Nepal-China was so profound because of the scale of the landslide, the quantity of water in the flood, the speed of the flood, and the number of people, communities, public works/infrastructure in the flood path," he said. "There was also little warning."
Risks in the High Mountains Asia
The Himalayas and the wider High Mountains Asia — an area that includes parts of China, Afghanistan, Nepal, India, Pakistan, Bhutan, Kazakhstan, Uzbekistan, Kyrgyzstan, and Tajikistan — are among the major epicenters for future glacier-related disasters, experts said. More than 9 million people in this region are at risk from glacial outbursts — when a lake bursts through or overtops its dam and drains rapidly — a 2023 Nature study found.
The region is nicknamed the "third pole" because it has the third-highest amount of ice in the world, after the Arctic and Antarctica.
Compounding this, any water, ice or debris can be channeled down the steep slopes into narrow valleys, meaning water and material can move quickly and travel huge distances, potentially inundating the downstream valleys where many people live.
For instance, in the recent Nepal glacial collapse, the resulting flood caused damage more than 60 miles (100 kilometers) away. The 2025 collapse of Birch glacier in Switzerland, by comparison — in which rock and ice also detached from a slope and destroyed the village of Blatten — traveled just 2.6 miles (4.2 km).
The Himalayas are also among the most seismically active places on Earth, and glaciers are frequently weakened by tremors, which can trigger avalanches, glacial lake outburst floods or glacial collapse.
The Himalayas are also warming twice as fast as the global average, reducing ice cover and increasing meltwater. "Permafrost and glacier cover help stabilize mountain slopes," Carey said. "They hold the rock in place." So as glaciers melt, the mountain slopes become more prone to avalanches.
Glacial meltwater can also act as a lubricant as it seeps into the bed of the glacier, which, in turn, can facilitate sliding, Bethan Davies, a professor of glaciology at Newcastle University in the U.K., told Live Science in an email.
The region's large population makes the geographic hazards there riskier, she added.
And with some of the biggest dams in the world going up in seismically active regions of the Himalayas and the Tibetan Plateau, new hazards are being introduced, Live Science previously reported.
A planet-wide risk
But another region on the other side of the world is also at very high risk of glacier-related disasters. Peru has 68% of the planet's tropical glaciers and has experienced disasters for decades, experts told Live Science.
"In Peru in 1970, 6,000 people died when an earthquake shook loose part of the glacier and rock on Mount Huascarán," Carey said. "The same slope had failed in 1962, causing a massive rock-ice landslide that buried the community of Ranrahirca, killing about 2,000 people in an event similar to the one recently in Nepal-China."
Lake Palcacocha, in Peru, is drained to reduce the risk of a glacial lake outburst flood. (Image credit: LUKA GONZALES via Getty Images)The Cordillera Blanca portion of the Andes in Peru is considered a particular hazard as a result of glacial lakes that are rapidly expanding due to glacial melt, fueled by increased temperatures driven by climate change. One such lake, called Lake Palococha, sits above the town of Huaraz, which is home to about 130,000 people. All told, experts have identified 528 lakes in Peru that are at risk of overflowing, with 58 considered "very high risk" due to their proximity to populations.
This threat spans the Andes. A 2023 study in the journal Nature noted that the number of glacial lakes in the Andes has risen by 93% in the past two decades — much more than the 37% increase in the High Mountains Asia.
In Europe, the Alps and cold regions like Scandinavia are potential hotspots for glacier-related disasters. Europe is warming faster than the global average.
In North America, meanwhile, Alaska is at risk for landslides and lake outbursts as glaciers collapse and retreat. Although many of the at-risk glaciers aren't in highly populated areas, there's a risk that glacial lakes could burst their banks and inundate the state's Suicide Basin, which frequently drains into and floods Juneau, Carey noted.
Glaciers or glacier-related landslides can also crash into the sea. "All areas with glaciers and all coastal areas where tsunami-like waves from a glacier collapse could inundate them," are at risk, Carey said.
How to reduce the risks
Better monitoring of glaciers and their lakes in at-risk regions can help mitigate the risks in the short and medium term, experts told Live Science.
The impact of good monitoring was evident last year in Blatten.
"The Birch Glacier was well monitored, and when it started to show signs of movement, the village below was evacuated," Davies said. Just one person — a 64-year-old shepherd who was outside the evacuation zone — died.
Glaciers across the planet are losing ice rapidly due to climate change. (Image credit: C3S/ECMWF/WGMS)However, the Himalayas are a vast region with many potential hazards, and local authorities do not have the resources to establish and run giant monitoring networks, experts said. Nor do local authorities typically have access to expensive rescue equipment, like helicopters that can quickly evacuate people who would otherwise be trapped, Carey said.
Carey noted that when a potential hazard is identified, authorities can take other steps, such as draining a swollen lake to try reducing the risk.
In Peru, over 70 years, for example, authorities "drained 34 glacial lakes over those decades, no doubt saving tens of thousands of lives," he said.
But disasters can still occur even with monitoring, draining and scientific assessment.
"Everyone, including me, had thought that engineering works to stabilize and contain Lake 513 [in Peru] back in the 1990s had secured it," Carey said."We were all wrong."
Despite all that work, in 2010, a giant avalanche generated a 82-foot-tall (25 m) tsunami that overtopped the lake's dam and flooded homes and nearby farmland.
In the long term, slowing global warming is the most sweeping way to reduce the risk of glacial collapse.
"Stronger climate action may prevent a worsening and increasing destabilisation of these high mountain environments," Davies said.
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'> The devastating Nepal floods highlighted the danger of glaciers. Here's where the next disaster may occur.
From the hundreds of iron fragments recovered from the gravel heaps, Trebsche and Berranger identified 193 complete iron bars and 307 partial bars, for a total of at least 500 bars that were lost centuries ago in the waters of the Danube. On average, the complete bars were 11.2 inches (28.5 centimeters) long and around 4.5 pounds (2 kilograms). Combined, the collection weighed around 2,200 pounds (1 metric ton).
But the Deinham iron bars did not represent finished products. Rather, the double-pointed, semifinished bars — sometimes called ingots — were rough-shaped, intermediate goods that a blacksmith eventually would have forged into other objects.
The semifinished iron bars would have been enough to forge approximately 500 swords, Trebsche said in the statement. "The iron from Deinham would have been sufficient to equip a large group of warriors with weapons," he said, or to produce up to 8,000 iron nails.
Because the iron was found during gravel extraction with a large bucket excavator, the original context of the archaeological find was destroyed. This erased archaeologists' opportunity to figure out how the metal ended up in the Danube.
"The possibility of ritual deposition cannot be excluded," the researchers wrote in the study, but "most studies on river finds have concluded that iron bars are losses incurred during transport." Before the invention of trains, most ancient cultures transported heavy goods via waterways.
If the iron bars were indeed lost in a shipwreck, they were probably produced somewhere upstream of the archaeological site, the researchers noted. Similar iron bars have been found in Manching, Germany, about 125 miles (200 kilometers) away, so it is plausible that the Deinham bars were forged in Bavaria, the team wrote in the study. Researchers are currently analyzing traces of elements in the bars, which may help to clarify their geographical origin.
"It is incredible that such a large quantity of iron was transported at once and was available in a single exchange transaction in the Late Iron Age," Trebsche said. "This finding demonstrates the increased capacities of iron production that were reached in the 3rd/2nd century BC in the Danube region."
'> 'Nothing short of a minor miracle': 'Rusty treasure' found in the Danube is full of 2,200-year-old iron bars that could equip an entire army with ...