The novel approach helps advance wireless sensor technology and paves the way for one day using large populations of inconspicuous sensors in implantable and wearable biomedical microdevices.
PROVIDENCE, R.I. [Brown University] - Tiny chips may equal a big breakthrough for a team of scientists led by Brown University engineers.
Writing in Nature Electronics, the research team describes a novel approach for a wireless communication network that can efficiently transmit, receive and decode data from thousands of microelectronic chips that are each no larger than a grain of salt.
The sensor network is designed so the chips can be implanted into the body or integrated into wearable devices. Each submillimeter-sized silicon sensor mimics how neurons in the brain communicate through spikes of electrical activity. The sensors detect specific events as spikes and then transmit that data wirelessly in real time using radio waves, saving both energy and bandwidth.
"Our brain works in a very sparse way," said Jihun Lee, a postdoctoral researcher at Brown and study lead author. "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."
This radiofrequency transmission scheme also makes the system scalable and tackles a common problem with current sensor communication networks: they all need to be perfectly synced to work well.
The researchers say the work marks a significant step forward in large-scale wireless sensor technology and may one day help shape how scientists collect and interpret information from these little silicon devices, especially since electronic sensors have become ubiquitous as a result of modern technology.
"We live in a world of sensors," said Arto Nurmikko, a professor in Brown's School of Engineering and 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."
That's why the researchers believe the system can help lay the foundation for the next generation of implantable and wearable biomedical sensors. 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.
"This is a milestone in terms of actually developing this type of spike-based wireless microsensor," Lee said. "If we continue to use conventional methods, we cannot collect the high channel data these applications will require in these kinds of next-generation systems."
