Brain Machine Interface

man wearing virtual reality headset using a virtual holographic interface of a brain

Imagine typing into your cell phone or computer without using a keyboard. This is becoming a reality through innovative work in brain-machine interface. The technology also has offered hope to those paralyzed by a stroke or injury.

The Woman Who Drank the Coffee

A brain-machine interface is a direct neural connection between the brain and a computer or machine. Although built on decades of research in multiple fields, the industry catapulted into headlines in 2012.

That’s when Catherine Hutchinson, left paralyzed and unable to speak following a stroke, used her mind to control a robotic arm and take a sip of coffee. Microchips were implanted into Hutchinson’s brain to allow a direct connection to a robotic arm used in the BrainGate2 clinical studies.

Afterward, better microchips enabled more fluid, mind-controlled movements and larger study groups. Efforts for less invasive connections also became a primary focus in the field.

Public and Private Funding

The BrainGate project continues its work to improve communication and mobility challenges and is also funding projects to develop assistive communication and treatments for conditions, such as epilepsy.

The Defense Advanced Research Projects Agency (DARPA) has launched a BRAIN Initiative and earmarked $65 million for research and development of smart prosthetics, creating implants that can record activity from over a million neurons and even improve memory.

The goal is to develop a compact wireless system, which would make it easier for users and improve the optics around the implant-based system. Ultimately, DARPA will collaborate with the FDA to advance to human trials.


Founded by Thomas Reardon, a child prodigy hired by Microsoft as a teenager, CTRL-Labs uses electrical signals sent from the brain as a powerful API between the brain and machines. They’re doing this without the wires and implants that make widespread adoption difficult for a squeamish publish. The prototype resembles a clunky armband worn around the lower or upper arm. It allows users to type — without a keyboard.

Slimmer versions in the works resemble a watch strap. You may soon abandon your keyboard and send commands to devices using your fingers on any surface and electrical signals from your brain.

The technology can also improve virtual reality, which alienates users due to controllers they can’t see. You may someday find it eerily satisfying to manipulate alternate realities with a brain-controlled machine.

How It Works

BMI works thanks to the way the brain functions. Neurons, individual nerves connected by axons and dendrites, make up a large part of the brain. Every time you move, think, feel or remember, your neurons go to work. Small electric signals zoom about on your brain’s neural network at 250 mph.

The axons and dendrites delivering electrical signals in your brain and throughout your body have a protective coating, called myelin. However, some of the signals leak through. BMI devices read these signals, interpret them and send instruction to a device, such as a robotic arm or a keyboard.

BMI Inputs — Allowing the Blind to See

BMI devices can also control inputs from machines and deliver them to the brain. For example, researchers can record the signal the optic nerve sends to the brain and translate it to the color blue. This may someday restore or provide sight to the blind.

The least invasive method uses a set of electrodes, called electroencephalography (EEG) attached to your scalp. However, the skull distorts the signals that get through.

Pros and Cons of Implants

To achieve a higher-resolution, scientists implant electrodes into the brain’s gray matter, beneath the skull. This creates better reception and enables implants in a specific area for improved control. However, it requires invasive surgery, and the implants tend to create scar tissue that blocks the signals.


Although implants offer hope to individuals with severe disabilities, their impact could be fleeting due to the current limitations of the technology. Many companies are pursuing noninvasive alternatives. For example, Carnegie Mellon University and the University of Minnesota are making strides toward a noninvasive BMI. These researchers created the first mind-controlled robotic arm, which can continuously track a computer cursor.

There are many exciting scenarios that could come out of further strides in brain machine interfaces, including those in medicine, which are likely to improve many lives in the future.