Plate Nº 29 · recorded October 10, 2026
Health & Medicine ResearchReported finding
MIT builds a 1.84-volt battery designed to dissolve in the body
MIT engineers built a 1.84-volt battery small enough to swallow that dissolves in the gut. In animal tests, it powered an RFID tag from the stomach and lifted hunger-hormone levels by about 50%.
By Nathan Brooks3 min read679 words
In brief
- The ingestible battery outputs 1.84 volts using magnesium and molybdenum trioxide electrodes.
- 20 minutes of electrical stimulation from the rectangular-bar battery lifted stomach ghrelin levels by about 50% in animal tests.
- Disc-shaped battery powered an RFID tag with a continuous transmission range of about 1.5 meters from inside the gastrointestinal tract.
- The two battery prototypes measure 7.5 millimeters across (disc) and 24 millimeters long (rectangular bar); both ran for about three days before fully dissolving in a few weeks.
- The MIT team expects to begin a clinical trial of the SAFARI ingestible system in roughly two years.
An ingestible 1.84-volt battery has powered an RFID tag from inside an animal's stomach and lifted hunger-hormone levels by about 50%. MIT researchers describe the design, made of magnesium and molybdenum trioxide, in Nature Chemical Engineering.
What problem does this solve?
For nearly a decade, Giovanni Traverso's lab at MIT has built ingestible capsules that monitor vital signs, deliver drugs, and detect opioid overdoses. Some need a built-in power source. Until now, the team relied on coin-cell batteries containing lithium or silver oxide, designs that could leak if their casing cracked in the gastrointestinal tract.
"For many of the systems we're developing, we need power, and we power the system through different ways," said Traverso, a professor of mechanical engineering at MIT, a gastroenterologist at Brigham and Women's Hospital, and an associate member of the Broad Institute of MIT and Harvard. "Often, we use batteries, so the question here was: Could we develop a battery that was bioresorbable, and then apply that across a range of application areas?"
How is the battery built?
Lead author Mehmet Girayhan Say, a former MIT postdoc, made two versions: a disc 7.5 millimeters across and a rectangular bar 24 millimeters long. Magnesium acts as the anode — the electrode that releases electrons. Molybdenum trioxide acts as the cathode, the electrode that accepts them.
An ionic liquid gel — a salt that stays liquid at body temperature — sits between them as the electrolyte, the substance that lets charged particles flow.
"Those materials are known to be relatively safe," Traverso said. "That was the biggest driver, thinking about materials that can be tolerated by humans."
How long does it last?
When dropped into a solution that mimics stomach acid, both shapes ran for about three days before their performance slowly fell. Within a few weeks, the structure had fully dissolved.
Could it really stimulate hunger?
To test the rectangular bar, the researchers wired it into a capsule first described in 2023. That device zaps the stomach lining with a small current, activating endocrine cells that release ghrelin — often called the hunger hormone. Boosting ghrelin could help patients with cachexia, the severe loss of body mass tied to cancer and other chronic illnesses.
Earlier capsules used two silver-oxide coin cells, the same type found in FDA-approved ingestible devices. Swapping them for the new battery made nearly every part of the capsule absorbable, save for a small printed circuit board.
In animal tests, 20 minutes of stimulation lifted stomach ghrelin levels by about 50%. The battery kept delivering continuous current for up to three days.
Could it also communicate?
The team also installed the disc-shaped battery in an RFID device — the radio technology used to track items wirelessly. An MIT version called SAFARI, reported in January, used passive RFID, tags that harvest energy from a reader's signal. That setup limits how far the tag can transmit.
With their own cell on board, the new capsule sent signals continuously from inside the gastrointestinal tract out to about 1.5 meters. The longer range and runtime could help clinicians confirm that patients take scheduled medication on time.
What happens next?
Traverso said his team plans a clinical trial of the SAFARI system within roughly two years. Success would also offer a second dividend: batteries that dissolve would not enter the sewage system as metal waste.
"The benefits are twofold: one, the ability to be bioresorbable, but also the potential to minimize environmental impact because the materials will be degraded in the environment as well," Traverso said.
"What makes this work exciting is that we were able to show that a bioresorbable battery is not just a concept," lead author Say added. "It can actually power clinically relevant functions inside the gastrointestinal tract and then simply dissolve."
The work received funding from Novo Nordisk, the Karl van Tassel Career Development Professorship, MIT's Department of Mechanical Engineering, the Brigham and Women's Hospital Division of Gastroenterology, and the U.S. Advanced Research Projects Agency for Health (ARPA-H).
via nature.com (Original)
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