Non-Invasive Ultrasound Brain-Computer Interface Startup Bridge Neurotech Launches With $13.5M, Competing In The Fast-Growing BCI Space
A New Contender In The Ultrasound BCI Race
Sam Altman-backed Merge Labs no longer stands alone in the niche of developing ultrasound-powered brain-computer interfaces. New entrant Bridge Neurotech has officially launched with $13.5 million in seed funding, backed by high-profile venture firm General Catalyst — an investor that has previously supported industry giants including Anduril, Anthropic, Airbnb and Stripe.
The startup joins a fast-expanding cohort of companies working to decode brain signals and translate them into tangible, actionable outputs. Well-known players across the BCI space, from Elon Musk’s Neuralink to Synchron, Paradromics and Precision Neuroscience, all currently focus on invasive systems built to help people who have lost motor function or the ability to speak.
Born From Frustration With Invasive BCI Tradeoffs
All existing leading BCI approaches rely on some form of surgical procedure, a core pain point that pushed Bridge founder and CEO Will Biederman to launch his own venture.
“It fundamentally comes down to a difference in vision,” Biederman explains. His PhD research work led to the development of the exact chip Neuralink licensed for its first generation of devices, but his goal for Bridge is to build a mass-accessible wearable system that serves far more users than a surgically implanted brain device. To date, only roughly 100 people worldwide have received implanted BCIs as part of clinical trials, including at least 21 volunteers testing Neuralink’s system.
“The risks of neurosurgery can never be fully minimized or dismissed, so the bar for safety and tangible benefit these devices need to clear is extremely high,” Biederman notes. “Nobody really wants a hole in their head.”
Wearable BCIs on the market today, however, have long struggled with poor signal quality: skin and skull bone dampen electrical brain signals before they reach external sensors, crippling device performance. This is exactly why most established BCI firms opt to record electrical impulses directly from neurons deep in the brain, an approach that has already proven capable of letting paralyzed users control electronics, move robotic arms and communicate in real time using only their thoughts.
Ultrasound As A Middle-Ground Alternative
Bridge Neurotech argues ultrasound technology offers a viable workaround for the limitations of both invasive implants and low-performance external sensors. The technology uses high-frequency sound waves that bounce off moving red blood cells to measure blood flow speed and direction; in the brain, shifts in blood flow directly track closely with underlying neural activity.
Maryam Shanechi, a University of Southern California neuroengineer, points out one key inherent tradeoff of the ultrasound approach: since it measures brain activity indirectly via blood flow rather than directly from neuron firing, there is an unavoidable multi-second delay between neural activation and the corresponding change in blood flow and volume.
“It captures a much slower variation in neural activity,” Shanechi says. “That works perfectly for many use cases, but the utility depends entirely on what you want the device to do.” The lag creates notable challenges for fast, real-time tasks such as instant robotic limb control or high-speed typing. Bridge plans to offset this gap using predictive AI models to cut lag and boost system performance. Biederman adds the company is exploring both consumer and medical use cases, though it has not shared concrete product roadmaps to date.
Shared Roots At Arbor Neuroscience
Both Bridge Neurotech and rival Merge Labs trace their origins to Arbor Neuroscience (previously named Forest Neurotech), a non-profit founded in 2023 by Biederman and fellow researchers Sumner Norman and Tyson Aflalo to pursue long-term, cross-disciplinary BCI work that is too complex for a single academic lab and too early stage for a commercial startup. The non-profit has already built an ultrasound brain function imaging device that is now in active clinical trials in the UK.
Merge Labs spun out of Forest Neurotech in January 2024, with Norman and Aflalo listed as co-founders alongside Sam Altman, researcher Mikhail Shapiro, and tech entrepreneurs Alex Blania and Sandro Herbig.
Early Clinical Trials And Non-Invasive Ambitions
Bridge has already launched its first observational clinical study in volunteers based in Redwood City, California. The trial involves no treatments or diagnoses: researchers place a small ultrasound probe on the side of the head of both healthy adults and patients who have previously undergone skull surgery, to record brain activity as participants complete listening, viewing, movement and speech tasks.
Bridge’s probes run on custom silicon chips developed by portable ultrasound firm Butterfly Network, and are designed to sit on the skull’s temporal window just above the ear — the thinnest section of the skull, which Biederman describes as “the easiest place to image through” because bone scatters and absorbs sound waves that create major barriers for non-invasive ultrasound imaging.
A 2024 study led by teams from Caltech and the University of Southern California confirmed ultrasound BCIs can successfully read and decode human brain activity, but required a section of the skull to be surgically removed and replaced with a transparent “window” to let sound waves pass through — a core technical hurdle Bridge is working to eliminate entirely.
“My entire vision is centered on non-invasive interfaces,” Biederman says. “I think that is where the biggest opportunity to help the largest number of people lies.”
