Nature is a never-ending source of inspiration for scientists, but our artificial devices usually don’t communicate well with the real thing. Now, researchers at Linköping University have created artificial organic neurons and synapses that can integrate with natural biological systems, and demonstrated this by making a Venus flytrap close on demand.
The new artificial neurons build on the team’s earlier versions, which were organic electrochemical circuits printed onto thin plastic film. Since they’re made out of polymers that can conduct either positive or negative ions, these circuits form the basis of transistors. In the new study, the team optimized these transistors and used them to build artificial neurons and synapses, and connect them to biological systems.
When the transistors detect concentrations of ions with certain charges, they switch, producing a signal that can then be picked up by other neurons. Importantly, biological neurons operate on these same ion signals, meaning artificial and natural nerve cells can be connected.
“We’ve developed ion-based neurons, similar to our own, that can be connected to biological systems,” said Chi-Yuan Yang, an author of the study. “Organic semiconductors have numerous advantages – they’re biocompatible, biodegradable, soft and formable. They only require low voltage to operate, which is completely harmless to both plants and vertebrates.”
To demonstrate the new system, the researchers hooked their artificial neurons up to a live Venus flytrap. And sure enough, electrical pulses from the artificial neurons were strong enough to trigger the flytrap to close its jaws, but at under 0.6 volts, gentle enough to not harm the plant.
Intriguingly, the team says that the neurons demonstrate a form of memory known as Hebbian learning, where repeated activation of particular synapses strengthens the neurons on either side, making that signal more effective over time.
The team says that the Venus flytrap was chosen for the demo because of how clear the reaction is, but ultimately the artificial neurons could be integrated with animal and even human neurons. They could find themselves bridging the gap between artificial and natural neurons for more responsive prosthetic limbs, implants, and robotics.
Other recent research has managed to make artificial synapses that communicate with synthetic electronic systems using neurotransmitter chemicals like dopamine.
The new research was published in the journal Nature Communications.
Source: Linköping University