Engineers have developed a brain-machine interface device that is small enough to attach to small groups of neurons.
Up to now, researchers working to develop more sensitive brain-machine interfaces have relied on electroencephalogram (EEG) readers and devices implanted in or near the brain through surgery. We have recently seen some of these devices, such as a device that helps improve concentration and another that can provide greater autonomy to the less-physically-abled. Now, engineers at the University of California at Berkeley have built a dust-sized, wireless sensor that can be sprinkled throughout the body and brain, and used to monitor and stimulate very small groups of neurons. Eventually, similar devices could be used to monitor internal organs in real time or to stimulate individual nerves to treat disorders such as epilepsy.
While most implanted sensors break down after a year or two, the motes are built from a thin film which could last in the body for up to a decade. For a power source, the neural dust uses ultrasound which, unlike radio waves, can penetrate nearly anywhere in the body. The sensors contain a piezoelectric crystal that converts ultrasound vibrations from outside the body into electricity to power a tiny, on-board transistor that is in contact with a nerve or muscle fibre. According to engineer Michel Maharbiz, one of the projects leads, “Having access to in-body telemetry has never been possible because there has been no way to put something super tiny super deep. But now I can take a speck of nothing and park it next to a nerve or organ, your GI tract or a muscle, and read out the data.”
The team is now working on shrinking the sensors from a 1 mm cube (about the size of a grain of sand) down to a cube just 50 microns on a side (around half the width of a human hair). At that size, the motes could be capable of attaching to individual nerves. They also plan to develop ways to focus the sounds waves on individual motes and to expand the motes’ ability to detect non-electrical signals, such as oxygen or hormone levels. In the future, the team envisions the neural dust being used to control robots and computers using thought, to stimulate nerves to treat diseases like epilepsy and Parkinson’s, by doctor’s to take very precise measurements, and even used to stimulate nerves to tell users to stop smoking. Will we all one day have neural dust sprinkled throughout our body to help us connect our brains with computers and stay healthy?