Imagine reaching for a cup of coffee and feeling its warmth. Feeling your fingers wrap around the handle. Sensing the weight as you lift it to your lips. For most of us, these sensations happen automatically. But for people with spinal cord injuries, that entire world of touch simply vanishes. Now, scientists are building a digital bridge to bring it back.
The Touch We Take for Granted
Most people don't realize how often they rely on touch instead of vision. When you're typing on your phone, walking down stairs, or picking up a flimsy cup of water, your sense of touch does most of the work. Your eyes might be looking elsewhere entirely.
"If you can't feel, you have to constantly watch your hand while doing anything, and you still risk spilling, crushing or dropping objects," explains Charles Greenspon, a neuroscientist at the University of Chicago who studies sensory restoration.
This constant visual monitoring is exhausting. It turns every simple task into a mental workout. And it's the reality for hundreds of thousands of people living with paralysis.
Wiring Sensation Directly Into the Brain
The solution sounds like science fiction: place tiny electrodes in the brain's touch center and use electrical pulses to recreate sensations. It's called intracortical microstimulation, or ICMS for short.
Here's how it works. The somatosensory cortex is a strip of brain tissue that processes touch from your entire body. Different spots in this region correspond to different body parts—your thumb, your palm, your fingertips. When you touch something, sensors in your skin send signals up through your spinal cord to these specific brain locations.
In paralyzed patients, the sensors still work and the brain regions are still intact. The problem is the spinal cord connection is broken. So researchers bypass it entirely. They implant arrays of 64 tiny electrodes directly into the somatosensory cortex. When they send electrical pulses through specific electrodes, patients feel touch on specific parts of their hand.
The first breakthrough came in 2018. Scientists at USC Keck School of Medicine and Caltech worked with a man who couldn't move or feel his limbs due to spinal cord injury. They stimulated his somatosensory cortex with electrode arrays. For the first time in years, he felt sensations in his paralyzed arm.
Making Touch Feel Real
Early experiments proved the concept worked. But could these artificial sensations feel natural? Could they be precise enough to actually use?
The answer, published in December 2024, is yes. Greenspon and his colleagues at the University of Chicago demonstrated something remarkable: these implanted electrodes create stable, precise sensations that last for years.
"If I stimulate an electrode on day one and a participant feels it on their thumb, we can test that same electrode on day 100, day 1,000, even many years later, and they still feel it in roughly the same spot," Greenspon says.
But the team went further. They discovered that activating two neighboring electrodes together creates a stronger, clearer sensation. And when they activate electrodes in sequence, patients feel something moving across their skin—a gentle gliding touch passing smoothly over their fingers.
This works because of how the brain naturally processes touch. Two electrodes next to each other don't create sensations that tile the hand in neat little patches. Instead, the sensory locations overlap. The brain fills in the gaps between discrete electrical pulses and interprets them as continuous, flowing experiences.
Beyond Simple Touch
Once researchers could create reliable touch sensations, they started building complexity. In 2024, a complementary study led by Giacomo Valle demonstrated that patients could feel movement and recognize complex shapes.
Participants identified letters of the alphabet electrically "traced" on their fingertips. They felt objects sliding along their skin. They could tell where on their hand they were being touched and how much pressure was being applied.
The real test came when researchers connected these sensory systems to robotic prosthetic arms. Participants used bionic arms to steady a steering wheel when it began to slip. They responded to pressure changes in real time. They could pick up delicate objects without crushing them or dropping them.
These aren't preprogrammed movements. The patients are feeling through the prosthetic and adjusting naturally, the way you or I would.
The Digital Bridge to Walking
While some researchers focused on restoring hand sensation, others tackled an even bigger challenge: walking. A spinal cord injury doesn't just eliminate sensation. It severs the connection between your brain's movement commands and your legs.
In 2023, a team published a breakthrough in Nature. They created what they call a brain-spine interface, or BSI—a digital bridge that connects brain signals directly to spinal cord stimulation.
The system uses 64 electrodes positioned over the sensorimotor cortex to record brain activity. When the patient thinks about walking, the system detects those signals wirelessly. Within milliseconds, it sends commands to 16 electrodes implanted in the spinal cord. These electrodes stimulate the nerves that control leg muscles.
The result? A patient with chronic tetraplegia—someone who couldn't walk for years—regained the ability to stand, walk, climb stairs, and traverse complex terrain. The system remained stable over a full year, including during independent use at home.
What surprised researchers most was what happened during neurorehabilitation. As the patient practiced walking with the BSI, their nervous system began to recover. Eventually, they could walk with crutches even when the BSI was switched off. The digital bridge had helped rebuild biological connections.
The Neuralink Factor
No discussion of neural implants in 2024 would be complete without mentioning Neuralink. Elon Musk's company implanted its first human patient in January 2024—a 29-year-old man paralyzed for eight years after a diving accident. They called the device "Telepathy N1."
By August, a second patient named Alex received the implant. Both demonstrated the ability to control digital devices with their thoughts. In November, Neuralink announced the CONVOY study, a trial to extend the technology to controlling assistive robotic arms.
Then in September came the Blindsight announcement. Neuralink's experimental implant aimed at restoring vision received "breakthrough device" status from the FDA. The concept is similar to touch restoration: bypass damaged eyes and optic nerves by stimulating the visual cortex directly.
Neuralink's approach differs from academic research in important ways. The company focuses on wireless, high-bandwidth brain-computer interfaces with thousands of electrode channels. Academic teams often use smaller arrays but focus more on understanding how to create natural, precise sensations.
Both approaches are advancing rapidly. And both face the same fundamental challenge: translating electrical patterns into experiences that feel real.
What Comes Next
The technology works. Patients can feel touch, control prosthetics, and even walk again. But these are still research studies with small numbers of participants. Scaling up will require solving several problems.
First, the systems need to become more robust and easier to use. Current setups require calibration and technical support. For neural implants to become practical medical devices, they need to work reliably with minimal maintenance.
Second, researchers need to expand the vocabulary of sensations. Right now, patients can feel location, pressure, and movement. But what about temperature? Texture? Pain? (Yes, pain—it's a crucial warning signal that keeps you from damaging your body.)
Third, the technology needs to become less invasive. Current systems require brain surgery to implant electrode arrays. Some researchers are exploring less invasive approaches, like electrodes placed on the brain's surface rather than inserted into tissue.
The applications extend beyond paralysis. University of Chicago researchers are collaborating on the Bionic Breast Project—an implantable device to restore sensation after mastectomy. Similar approaches might help people with diabetic neuropathy, stroke, or limb loss.
The Man Behind the Science
Much of this progress traces back to Sliman Bensmaia, a neuroscientist who led pioneering touch restoration research at the University of Chicago. Bensmaia's lab figured out how to decode the language the brain uses to represent touch. They learned which patterns of electrical stimulation create which sensations.
Bensmaia passed away unexpectedly in 2023 at age 50. But his students and collaborators continue the work. Greenspon, who trained in Bensmaia's lab, now leads studies building on those foundations.
"Sliman always said the goal wasn't just to prove this was possible," Greenspon recalls. "It was to make it good enough that people would actually want to use it."
That's the standard these systems are approaching. Not just functional, but genuinely helpful. Not just technically impressive, but practically useful.
Feeling the Future
We're watching something remarkable unfold. For the first time, we can give people back sensations they lost years ago. We can help paralyzed patients feel a handshake, sense when they're about to drop something, walk without watching every step.
The technology isn't perfect yet. It's not ready for widespread use. But the trajectory is clear. Within a decade, neural implants that restore sensation could transition from experimental procedures to established medical treatments.
The implications go beyond the practical. Touch connects us to the world and to each other. It's how we experience comfort, pleasure, and physical connection. Restoring it means restoring a fundamental part of being human.
When that man in the 2018 USC study felt sensations in his paralyzed arm for the first time, he didn't just regain a function. He regained a piece of himself he thought was gone forever. That's what this technology ultimately offers: not just movement or sensation, but wholeness.