Engineering news
Developed at Brown University in Rhode Island, thousands of the microelectronic chips could be either implanted into the body or integrated into wearable devices.
“Each submillimetre-sized silicon sensor mimics how neurons in the brain communicate through spikes of electrical activity,” the researchers said. The sensors detect specific events as spikes and then transmit that data wirelessly in real-time using radio waves, saving energy and bandwidth.
“Our brain works in a very sparse way,” said Jihun Lee, lead author of the new study. “Neurons do not fire all the time. They compress data and fire sparsely so that they are very efficient.
“We are mimicking that structure here in our wireless telecommunication approach. The sensors would not be sending out data all the time – they’d just be sending relevant data as needed as short bursts of electrical spikes, and they would be able to do so independently of the other sensors and without coordinating with a central receiver. By doing this, we would manage to save a lot of energy and avoid flooding our central receiver hub with less meaningful data.”
That approach makes the system scalable, the researchers said, and avoids the challenge of perfectly synchronising each of the sensors.
The team tested the system using 78 sensors in the lab and found they were able to collect and send data with few errors, even when the sensors were transmitting at different times. Through simulations, they showed how to decode data collected from the brains of primates using about 8,000 hypothetically implanted sensors.
“We live in a world of sensors,” said Professor Arto Nurmikko, the study’s senior author. “They are all over the place. They're certainly in our automobiles, they are in so many places of work and increasingly getting into our homes. The most demanding environment for these sensors will always be inside the human body.”
The system could help “lay the foundation for the next generation of implantable and wearable biomedical sensors”, the researchers claimed. “There is a growing need in medicine for microdevices that are efficient, unobtrusive and unnoticeable but that also operate as part of a large ensembles to map physiological activity across an entire area of interest,” they added.
External transceivers supply wireless power to the sensors as they transmit their data, meaning they just need to be within range of the energy waves sent out by the transceiver to get a charge. Operating without being plugged into a power source or battery could make them suitable for many different situations.
The work built on previous research from Nurmikko’s lab at Brown, which introduced a new kind of neural interface system called ‘neurograins’. This system used a coordinated network of tiny wireless sensors to record and stimulate brain activity.
The next steps include optimising the system for reduced power consumption, the researchers said, and exploring broader applications beyond neurotechnology.
The work was published in Nature Electronics.
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.