Scientists at Northwestern University printed tiny electronic neurons that act like real brain cells. The devices are thin, cheap, and can make electrical signals that look just like the ones living neurons use.
When the printed neurons were placed on slices of a mouse brain, they caused the natural neurons to fire. This shows that the artificial cells can talk directly to living brain tissue.
Why This Matters
Being able to connect electronics to the nervous system could help create new brain‑machine interfaces and neuro‑prosthetics. Imagine implants that bring back hearing, sight, or movement.
The same technology could also inspire computers that work more like the brain—fast, smart, and using far less power than today’s chips.
The findings will appear in the journal Nature Nanotechnology on April 15.
Brain vs. Silicon
Today's computers pack billions of identical transistors onto flat silicon chips. Once made, the chips cannot change.
The brain is different. It has many types of neurons, each with a special job, arranged in a soft 3‑D network that reshapes itself while we learn.
To copy this flexibility, researchers used soft, printable materials instead of rigid silicon.
How the Printed Neurons Work
The team printed layers of two nanomaterials: molybdenum disulfide (MoS2) as a semiconductor and graphene as a conductor. These inks were sprayed onto a flexible plastic sheet using an aerosol jet printer.
During printing, a thin polymer layer was left on purpose. When electricity flows, the polymer breaks apart in spots, forming a tiny conductive filament. This filament creates a sudden burst of current—just like a neuron firing.
Each printed neuron can make many kinds of signals: single spikes, steady firing, or bursts. Because they can produce complex patterns, fewer devices are needed for advanced tasks, which saves energy.
Testing with Real Brain Tissue
To see if the signals could truly interact with biology, the researchers applied them to mouse cerebellum slices. The artificial spikes matched the timing and length of natural brain signals and reliably activated the real neurons.
“Previous artificial neurons were either too slow or too fast,” said the lead scientist. “Our printed neurons fire at the right speed and shape, so living cells respond just like they would to a real brain signal.”
Low‑Cost and Green Production
The printing process is simple, cheap, and wastes almost no material because the ink is deposited only where needed. This makes the technology more sustainable.
Energy‑efficient hardware matters because modern AI systems use huge amounts of power and water for cooling. The printed neurons could help build computers that need far less electricity, easing the strain on power grids and water supplies.
The research was funded by the National Science Foundation.