MIT engineers have created a tiny emergency implant that could save lives by protecting patients from hypoglycemia – a dangerous drop in blood sugar. The coin-sized device, which sits under the skin, can automatically release a dose of glucagon when blood sugar levels get too low. It can also be activated wirelessly by a connected sensor or manually in emergencies.
For millions of people living with Type 1 diabetes, hypoglycemia is a constant fear. When glucose levels fall sharply, it can lead to confusion, seizures, loss of consciousness, and even death if not treated quickly.
Normally, patients inject glucagon to raise blood sugar levels, but the process requires them to recognize the warning signs in time, mostly during sleep, or for children who cannot administer the injection themselves.
“This is a small, emergency-event device that can be placed under the skin, where it is ready to act if the patient’s blood sugar drops too low,” said Daniel Anderson, a professor of chemical engineering at MIT and senior author of the study. “Our goal was to build a device that is always ready to protect patients from low blood sugar.”
The device is also designed to help in situations where patients might not wake up to an alarm from their glucose monitor, or when young patients and those living alone cannot respond quickly enough.
The new device is built with advanced engineering. It contains a tiny drug reservoir made using 3D printing technology and is sealed with a special metal called nickel-titanium alloy. This metal has a unique property—it changes shape when heated.
When the device detects low blood sugar or receives a wireless signal from a glucose monitor, a small electric current heats the metal to about 40 degrees Celsius. This change causes the metal to curl and open the reservoir, releasing the powdered glucagon into the bloodstream.
“One of the key features of this type of digital drug delivery system is that you can have it talk to sensors,” said Siddharth Krishnan, lead author of the study and a former MIT research scientist, now an assistant professor at Stanford University. “In this case, the continuous glucose-monitoring technology that a lot of patients use is something that would be easy for these types of devices to interface with.”
Unlike liquid glucagon, which can break down over time, the powdered form used in the device remains stable for long periods. This ensures the drug is ready whenever it is needed.
To test the device, researchers implanted it in diabetic mice and monitored their blood sugar levels. When levels began to drop, they activated the device wirelessly. Within 10 minutes, the mice’s blood sugar stabilized and stayed within a safe range.
The team also experimented with storing and releasing epinephrine, a drug commonly used in emergencies such as heart attacks or severe allergic reactions. They found that 10 minutes after activation, epinephrine levels in the bloodstream increased, proving that the device could have broader uses beyond diabetes care.
Even after four weeks in the body, the device continued to function, despite scar tissue forming around it. Researchers are now working on extending the device’s lifespan to one year or more before it needs replacement.
“We don’t know exactly what that is—maybe a year, maybe a few years, and we’re currently working on establishing what the optimal lifetime is,” Krishnan said. “But then after that, it would need to be replaced.”
The MIT team plans further animal studies and hopes to start human trials within three years. If successful, this device could provide a sense of security for diabetic patients and their families.
“It’s really exciting to see our team accomplish this, which I hope will someday help diabetic patients and could more broadly provide a new paradigm for delivering any emergency medicine,” said Robert Langer, a co-author of the study and MIT’s Koch Institute Professor.
The findings were published in Nature Biomedical Engineering, and the research was funded by the Leona M. and Harry B. Helmsley Charitable Trust and the National Institutes of Health.
“This device could be a breakthrough that frees patients and their families from the fear of hypoglycemia,” Anderson said. “It could also be adapted for many more emergency medications in the future.”
