The size of a grain of rice, the impact of a medical revolution. The pacemaker just developed by a team from Northwestern University It challenges every previous conception of a cardiac device. It is tiny, dissolvable, implantable with a simple syringe, and (not insignificantly) could prevent tragedies like the one that struck the first man on the Moon.
Think about the babies born each year with heart problems: saving their lives would require only temporary support. Now imagine avoiding invasive surgery, replacing it with a simple injection of a device that will do its job and then disappear naturally. That would simply go down in history.
When lowercase means revolutionary
Every year, approximately 1% of newborns comes into the world with a heart that struggles to find its own rhythm. A percentage that seems small until we transform it into faces, into stories, into families waiting with bated breath. Most of these little ones require only temporary support, just seven days, the time needed for the heart to learn to beat correctly on its own.
Unfortunately, in parts of the world where access to advanced medical care is a mirage, what should be a simple procedure often becomes a curse. Traditional pacemakers require surgeons to “sew” electrodes directly onto the heart, then connect them to an external unit via wires that emerge from the patient’s chest.
A nightmare of potential complications: infections, damaged tissue, blood clots. And sometimes, the threads get caught in the scar tissue, further complicating the situation.
It is precisely this procedure that led to the death of the astronaut. Neil Armstrong. “He had a temporary pacemaker after bypass surgery. When the wires were removed, he had internal bleeding,” he explains. Igor Yefimov, experimental cardiologist and co-lead of the study published in Nature, in a statement that made me reflect on the fragility of life, even for those who have walked on the moon.
Pacemaker, the evolution of a turning point
In 2021, a team from Northwestern University, of which he was a part Efimov, had already presented a temporary biodegradable pacemaker, the size of a coin, without bulky batteries, rigid components or wires. The device was based on communication protocols similar to those used in tags RFID and in smartphones to complete electronic payments.
But this required the pacemaker to include a built-in antenna to transmit radio frequency commands. “Our original pacemaker worked well. It was thin, flexible, and completely resorbable. But the size of its receiving antenna limited our ability to miniaturize it,” explained its co-creator and bioelectronics pioneer john rogers.
Rogers, Efimov and their collaborators spent the next few years researching ways to shrink their temporary pacemaker to an even smaller size. Eventually they realized they could replace the radio antenna with a design that targets light-based data transmission. And everything changed.
A flash of light
The new device has replaced the original power source with a galvanic cell, a type of battery that converts chemical energy into electrical energy. The pacemaker relies on two metal electrodes that generate an electrical current after interacting with surrounding biofluids.
“Infrared light penetrates the body very well,” he said. Efimov. “If you hold a flashlight against the palm of your hand, you will see the light through the other side. It turns out that our bodies are excellent conductors of light.”
It strikes me how poetic this synergy between technology and biology is: a heart guided by light, a beat regulated by invisible rays that pass through skin, bones and muscles as if they were glass.
Microscopic Pacemaker: Big Impact in Tiny Size
The final result is a device 1 mm thick, just 1,8 mm wide and 3,5 mm long, capable of providing as much electrical stimulation as a standard pacemaker. “We have developed what we know of as the world’s smallest pacemaker,” Rogers said with pride that shone through his words.
Because its materials dissolve safely over time, the pacemaker does not require any invasive follow-up surgery to remove it. This dramatically reduces the potential for post-operative complications and trauma.
The future? It's "polyphonic"
But why stop at just one tiny pacemaker? Efimov, Rogers and their colleagues believe that further advances could enable the implementation of more devices in the whole heart. Once implanted, the designers could coordinate them to move independently or together based on specific wavelengths of light, creating a sort of perfectly synchronized cardiac orchestra.
The device’s size also means it could be incorporated into other implantable devices such as transcatheter aortic valve replacements, pain inhibitors, nerve and bone restoration techniques. These future possibilities, however, all go back to the team’s original goal.
“Our main motivation was children,” Efimov said. “Now we can put this tiny pacemaker on a child’s heart and stimulate it with a soft, gentle wearable device.”
When I think of this tiny device “floating” in the chest of a newborn, gently regulating its still uncertain heartbeats, I perceive something that goes beyond technological wonder. Like a whisper that guides the song of a heart.
