One small step for neural interfaces: Stanford researchers show artificial synapse can communicate with living cell

Stanford University researchers have demonstrated the ability of their engineered, artificial synapses to communicate with living cells, a potential step in creating computers that can interface directly with the human brain.

The artificial synapse used by the researchers was first developed at the university in 2017, Stanford News reported. In 2019, university researchers were first able to show the artificial synapses working together in an array.

The first test of a biohybrid version that coupled the artificial synapse with a living cell was recently published in “Nature Materials.”

“This paper really highlights the unique strength of the materials that we use in being able to interact with living matter,” Alberto Salleo, professor of materials science and engineering at Stanford and co-senior author of the paper, told Stanford News. “The cells are happy sitting on the soft polymer. But the compatibility goes deeper: These materials work with the same molecules neurons use naturally.”

The artificial synapses are made from organic materials, according to Stanford News. Unlike other potential brain-computer interface methods that rely on electrical signals, the organically-based synapse can communicate in the same way the human brain does, with chemically-based signals.

This way the artificial synapse is able to interact with a living neuron as if it were another neuron. 

By receiving and retaining signals transmitted via soft polymer electrodes in this fashion, the artificial synapses is able to replicate something similar to the learning process that occurs in living brains.

The process also eliminates a step in normal computing, where information must be processed before it is stored. This makes it more energy-efficient as well.

“In a biological synapse, essentially everything is controlled by chemical interactions at the synaptic junction. Whenever the cells communicate with one another, they’re using chemistry,” Scott Keene, a graduate student at Stanford and co-lead author of the paper, told Stanford News. “Being able to interact with the brain’s natural chemistry gives the device added utility.”

While the research is promising,  it's still only preliminary.

“It’s a demonstration that this communication melding chemistry and electricity is possible,” Salleo told Stanford News. “You could say it’s a first step toward a brain-machine interface, but it’s a tiny, tiny very first step.”