Bridge Neurotech Launches to Challenge Merge Labs in Brain Tech

Bridge Neurotech is entering the brain-computer interface race with a new approach that skips surgery entirely. Wired reports the company has raised $13.5 million from General Catalyst and other investors. Its founder, Will Biederman, previously developed the chip that Neuralink licensed for its first implants.

Most existing brain-computer interfaces require implanting electrodes directly into the brain. Only about 100 people worldwide have received such implants in clinical trials. Biederman told Wired that the risks of neurosurgery are too high for many potential users. "Nobody really wants a hole in their head," he said.

The Ultrasound Alternative

Bridge Neurotech plans to use ultrasound to read brain activity. High-frequency sound waves bounce off moving red blood cells, measuring blood flow changes that correlate with neural activity. The device will be worn on the side of the head, near the temple, and look "something close to headphones," Biederman said.

But ultrasound has a limitation: it measures blood flow indirectly, creating a delay of a few seconds between neural firing and detection. Maryam Shanechi, a neuroengineer at the University of Southern California, told Wired that this lag could be fine for many applications but might pose problems for fast-paced tasks like moving a robotic arm or typing instantly.

"It captures a slower variation in neural activity."

— Maryam Shanechi, neuroengineer at the University of Southern California, as told to Wired

Challenges and Plans

Bridge faces a major technical hurdle: bone scatters and absorbs sound, making it hard to image through the skull. The company will place its probe at the temporal window, the thinnest part of the skull. A 2024 study showed ultrasound could decode brain activity, but only after removing a piece of skull.

Biederman says Bridge will use predictive AI models to compensate for the lag. The company is starting an observational clinical study in Redwood City, California, using probes made with silicon chips from Butterfly Network. Healthy adults and people who have had skull surgery will participate while listening, watching, moving, and speaking.

Bridge Neurotech and its competitor Merge Labs both trace back to Arbor Neuroscience, a nonprofit co-founded by Biederman and researchers Sumner Norman and Tyson Aflalo. Merge Labs spun out in January and counts Sam Altman among its cofounders. Bridge is focused on noninvasive interfaces, with both consumer and medical applications under consideration.

• brain-computer interface
• Bridge Neurotech
• Merge Labs
• Neuralink
• ultrasound
• Will Biederman