How Our Own Cells Could Implant The Next Generation Of Nonsurgical Brain Microchips

(Posted on Friday, January 2, 2026)

Treating brain diseases is extraordinarily challenging, because drugs often work poorly and implants require risky surgery that can jeopardize critical brain functions. A group at MIT has sought a different approach, using the natural ability of living cells to detect diseased brain areas and ferry microscopic electronic devices directly to these regions. These devices, smaller than a single cell, can then be remotely activated with infrared light to modulate local brain activity.

When we imagine a brain implant, we usually picture an operating room: shaved scalp, opened skull, electrodes carefully placed in the tissue. Instead of implants, these devices function as non-surgical, microchips carried by the body’s own cells. Light from outside the head would then power these devices, nudging nearby neurons without a single incision.

The researchers behind this study call the concept Circulatronics: electronics that circulate.

Tiny Devices That Ride the Bloodstream

The first challenge is size. To slip through blood vessels without blocking them, the devices have to be as small as or smaller than the cells already in circulation. The team built subcellular-sized, wireless electronic devices, small discs only a few micrometers across and a couple hundred nanometers thick. Despite their minuscule form, these devices can harvest energy from light and generate tiny electrical signals.

Instead of wires or batteries, the devices act like microscopic solar panels. When light reaches them, they produce a steady electrical potential, enough to influence nearby brain cells. Electrical stimulation is a well-established tool in neuroscience and medicine, capable of modulating neural activity in ways that can help treat movement disorders, mood disorders and some forms of chronic pain. The team chose near-infrared wavelengths that can pass through the skull and several centimeters of brain tissue, allowing the devices to be powered from outside the body. Once fabricated, the devices are released from their wafer into solution, becoming free-floating chips that can move in fluid just like cells do.

Turning Immune Cells into Living Couriers

Tiny devices alone won’t home in on the right brain area. For that, the researchers turned to the body’s natural search-and-rescue system: immune cells. Certain immune cells are drawn to inflammation, which is the hallmark for many neurodegenerative diseases and brain cancers. They circulate in the blood, sense trouble and cross into the brain where tissue is diseased or injured.

The team chemically attached the devices to the surface of mouse immune cells, creating cell-electronics hybrids. This attachment is achieved through specialized surface chemistry that keeps the bond stable even as cells squeeze through tight biological barriers. Most hybrids stayed intact during circulation.

In mice, the researchers induced a small, localized inflammatory spot deep in the brain, in a region important for motor control. They then injected the hybrids into the blood, with no cranial surgery. Over the next three days, the immune cells followed their natural programming. They traveled through the bloodstream, sensed the inflamed region, crossed into the brain and self-implanted their electronic cargo right where it was needed.

Lighting Up Deep Brain Circuits

Once these tiny devices settle into the right spot in the brain, they can turn gentle light from outside the head into focused electrical nudges deep inside the brain. Neurons, the cells that help us think, move and feel, respond to electricity. When the devices receive near-infrared light, they release tiny bursts of electrical energy, just enough to encourage nearby neurons to fire. This effect is extremely precise; only the neurons sitting close to the device respond.

This means that stimulation can be targeted to one very specific location, even when that location is deep and normally reachable only by surgery. Instead of placing an electrode by surgery, the body delivers these microscopic stimulators on its own, and light becomes the remote control. At its heart, the finding reveals a new possibility: using the combination of immune cells and light to gently guide the brain’s signals from the outside, with no wires, no batteries and no incisions.

Inside the Lab: A Conversation with the Researchers

We interviewed Dr. Deblina Sarkar, a key member of the team at the MIT Media Lab, to understand how Circulatronics works, how the chips interface with cells, and how the team approaches safety and public trust.

Q: For someone who’s never heard the word Circulatronics, how would you explain this technology?

A: “The problem we are solving is the impossible choice faced by millions of people with devastating brain diseases: undergo risky brain surgery, or continue suffering through the disease which drugs cannot cure. We already know that precisely stimulating neurons can help treat these conditions, but doing so today is extremely invasive.

What we have developed are tiny electronic devices that can travel through body fluids and autonomously find their target regions, with no external guidance or imaging. They provide very precise electrical stimulation of neurons without the need for surgery. It’s important to distinguish this from simple injectable devices; you don’t need to inject into the brain, make a hole, or place anything directly into brain tissue. These devices self-implant.”

Q: Today’s patients with Parkinson’s, epilepsy or severe depression often need brain surgery or bulky devices for stimulation. If your approach eventually makes it to the clinic, what could it change in a patient’s journey, from diagnosis to treatment day and recovery, compared with the deep-brain stimulation surgeries we use now?

A: “Patients could benefit in multiple ways. Brain surgeries cost hundreds of thousands of dollars; this approach would greatly reduce those costs. It would also make advanced treatment far more accessible in developing countries. Right now, less than 1 percent of eligible patients receive surgical treatments; Circulatronics could dramatically improve this.

Even for patients who can afford surgery, some brain regions simply cannot be accessed safely. For example, the pediatric brain cancer DIPG sits in a very sensitive area where surgery is challenging. But the circulatory system reaches everywhere, and so do our Circulatronics.

In addition, some diseases have pathological sites spread throughout the brain, as in Alzheimer’s or diffuse brain cancers. It isn’t feasible to surgically implant multiple electrodes. And sometimes the pathological sites are so small they can’t be detected through imaging; this technology can detect and self-implant at those sites.”

Q: We all remember the conspiracy theories during COVID claiming vaccines were secretly implanting microchips in people. Now you’re working on real, wireless brain implants delivered through a vein. How do you think about communicating this research so it isn’t misunderstood or weaponized by misinformation?

A: “I think it’s crucial to communicate the human stories behind the science. When someone who is blind could potentially regain meaningful vision without needing surgery, or when a person with an otherwise untreatable neurological condition or brain disease might finally have hope: that is the heart of this work. When people understand that the purpose is healing and restoration, the conversation shifts away from fear and toward compassion and possibility.

Recently, I met the parents of a 10 year old child with terminal brain cancer who told me that every existing treatment had failed them. During my research journey, I have met many families facing devastating neurological diseases. Families like theirs are thinking about staying alive, about giving their loved ones a future. That human urgency is what drives us.

At the same time, we know how misinformation can distort scientific progress, so we communicate our science with complete transparency. When people understand that this technology exists because families desperately need better options, they see it for what it truly is: a compassionate attempt to relieve suffering and restore hope where very little currently exists.”

The Road Ahead

Whenever we talk about putting anything into the body, even something incredibly tiny, safety comes first. The encouraging news is that these cell-carried devices appear gentle on the body. In lab tests, they didn’t harm the immune cells that carried them or the neurons they eventually sat near. In animals, basic health markers, behavior and organ function stayed normal whether or not the animals received the hybrids.

The devices don’t linger forever. The cell-device pairs gradually cleared out of the bloodstream on their own, and even when the devices were placed directly into brain tissue for testing, the surrounding cells looked healthy months later. If this technology continues to prove safe, it could someday offer ways to treat brain conditions without surgery, using the body’s own cells and a bit of light. It hints at a world where getting help for the brain is less an operation and more like a routine procedure, one that works with the body rather than against it.