Health
Brain implants that don’t leave scars

Axoft’s flexible brain implant.

Axoft Inc.

Kirsten Mabry

Harvard Office of Technology Development

August 14, 2025 6 min read

Harvard startup is developing a softer device to monitor head injuries

Traumatic brain injuries vary in severity from mild to life-threatening, but neurologists have limited tools to assess the damage. While examinations and external imaging can help, neural probes — devices that create brain-computer interfaces — are even better. The problem? They are made of rigid materials that scar the brain.

Axoft, a startup launched out of Harvard in 2021, is developing a softer alternative, one the company’s researchers say could be inserted into the brain without disturbing its gel-like consistency but is durable enough to deliver accurate neural data.

“With a brain-computer interface, we can determine very precisely what’s happening in the brains of the patients — if they are conscious, if they are not conscious, if they are vegetative, if they are recovering, or if their state is degrading,” said Paul Le Floch, co-founder and CEO of Axoft, who received his Ph.D. in materials science from Harvard.

Clinicians have used neural probes for decades. When inserted into the brain, they measure electrical activity with much more accuracy than external neural imaging. But traditionally, neural probes have been made of rigid materials, which damage the surrounding, highly flexible brain tissue — like razor blades in gel, said Le Floch. Damage to the brain makes neural probes less effective, because the brain responds by surrounding them with scar tissue. Encapsulated in that more rigid tissue, the probes cannot communicate as readily with the neurons around them. Plus, rigid devices can only stay implanted for a short time before they significantly scar the brain. As more sensors are added to a neural probe — an essential element of gathering as much brain activity data as possible — the probes become even more rigid.

Traditionally, neural probes have been made of rigid materials, which damage the surrounding, highly flexible brain tissue — like razor blades in gel.

Le Floch and his collaborators understood that they needed a softer alternative to existing neural probes. “The problem is: Soft materials are not very high-performance,” he said.

During a Ph.D. focused on material science and polymers at Harvard, Le Floch began working as a graduate student in the lab of Jia Liu, an assistant professor of bioengineering at the John A. Paulson School of Engineering and Applied Sciences. Le Floch and Liu focused on an intractable problem: engineering neural probes that worked better for the brain.

Le Floch and Liu collaborated with Tianyang Ye, Ph.D. ’20, a graduate student and then postdoctoral scholar at Harvard specializing in nanoelectronics, as well as a fellow at the Office of Technology Development (OTD), where he worked on commercialization strategies for academic innovations. Ye is now Axoft’s chief technology officer, as well as a co-founder. While Le Floch engineered a higher-performance, soft material that could be inserted into the brain without harming it, Ye designed the electronics that could transmit the data for analysis.

The resulting neural probe is “very biocompatible, because it’s so small, but also very soft,” said Le Floch. “It creates less damage within tissues over time.”

Paul Le Floch (left) and Jia Liu.

Axoft’s novel material, Fleuron, is thousands to millions of times softer and more flexible than the material used in modern neural probes. At the same time, Fleuron is a photoresist, applicable for the chip-fabrication process. As a result, the probe can easily fit more than 1,000 sensors, delivering precise brain-signal data to clinicians.

“In the last few decades, we’ve gone from measuring one neuron, to 10 neurons, to hundreds of neurons — now we’re getting into thousands,” said Le Floch. Those greater multitudes allow researchers to “learn more about the brain and develop new diagnoses and therapies.”

Axoft is working to double the number of electrodes its probe can host every year as it continues to develop the technology. “This will significantly increase the number of neurons Axoft’s probes can measure and stimulate,” said Liu, who helped co-found the company and joined as a scientific adviser.

Brain implants are not necessary for every patient with neurological damage, Le Floch says, but the company has already experienced significant interest from neurologists who have struggled to measure the brain activity of unresponsive patients with acute and traumatic brain injuries.

“We see a big need from a patient perspective.”
Paul Le Floch, Axoft CEO

The impact of the startup’s work was clear from the beginning, according to Christopher Petty, OTD director of business development in physical sciences. “From our point of view, we’re always talking about this mission of taking academically generated knowledge and making a difference in the world with it. This is that in spades,” he said. “That’s the point of everything we’re doing.”

OTD safeguarded the intellectual property of the core discoveries, connected Axoft’s team with potential investors and structured the startup’s license to further develop the technology, while helping its founding researchers think about real-world applications and the journey from testing to commercialization.

Helping a medical device startup flourish, says Petty, differs from the process for a software startup. The clinical trials necessary for approval can take a significant amount of time and cost a lot of money, but there’s also a much more clearly defined path to market. “There’s a clear set of milestones,” Petty said.

Since its founding, Axoft has been working to hurdle those milestones. The company has raised more than $18 million in funding thus far. In 2025, it completed its first human trial at the Panama Clinic in Panama, which demonstrated that the implants were safe to insert and remove and didn’t create additional risks for the brain in the process. The team also determined that the probe could differentiate when patients are conscious or unconscious (due to anesthesia), the latter of which mimics a coma-like state. Within a few minutes, the team was able to measure brain states in the way a functional MRI might over several hours.

Now, in order to generate more preclinical data, Axoft is working with clinicians at Massachusetts General Hospital on porcine models of traumatic brain injury. Le Floch expects Axoft will be able to begin another in-human study with the hospital in the next year.

In 2027, Axoft is targeting an FDA-managed clinical trial focused on individuals with traumatic brain injuries, in whom the device can measure recovery and consciousness. If all goes well, the devices could be available to physicians by 2028. Le Floch believes the implants could quickly scale to hundreds of patients.

“We see a big need from a patient perspective, and there is already an ecosystem in hospitals for using neuromonitoring devices,” he said.

This research received federal funding from the National Science Foundation.