Engineers at Northwestern University have printed artificial neurons from nanomaterials that communicate with real brain cells. The devices produce the same complex firing patterns as biological neurons and triggered activity in living brain tissue during laboratory tests. The study was published on April 15, 2026, in the journal Nature Nanotechnology.
The Energy Problem of Modern Computing
Each time a large language model answers a query, a data center consumes the energy of a small household. The human brain processes comparable tasks with a fraction of that energy. The gap is quantifiable: the brain is roughly 100,000 times more energy-efficient than today's digital computers.
Neuromorphic electronics attempts to translate the operating principles of the brain into hardware. Instead of classical logic gates, components should function like biological neurons: integrating pulses, crossing thresholds, and relaying signals. Previous approaches had a persistent problem — artificial neurons fired either too fast or too slow, not in the biological rhythm.
Printed Neurons From Two Ingredients
The team led by Mark Hersam, professor of materials science at Northwestern University, and Indira Raman, a neurobiologist there, chose two nanomaterials: molybdenum disulfide as a semiconductor and graphene as a conductor. Both can be used as electronic ink. Using aerosol jet printing, they were deposited layer by layer onto flexible polymer substrates, similar to inkjet printing but at the sub-micrometer scale.
The decisive step lay in post-processing: the polymer substrate was heated until it partially decomposed, forming conductive filaments that concentrate electrical current. These tiny channels allow the devices to generate neuronal firing patterns under voltage without complex external circuitry.
The results surpass previous attempts on one critical measure: the printed neurons produce not just simple, uniform pulses but the same patterns real neurons generate in the living brain. Single action potentials, sustained activation, and the burst patterns typical of many brain regions — short, high-frequency pulse sequences — can all be reproduced.
Test on Living Brain Slices
The decisive evidence came from an experiment on mouse brain slices. The printed neurons were placed against cerebellar tissue sections and electrically activated. Result: the artificial signals triggered activity in biological nerve cells. This coupling between printed hardware and living tissue is the core of the breakthrough.
Vinod Sangwan, materials scientist and co-author of the study, highlights the practical advantage of the manufacturing method: aerosol jet printing is an additive process that wastes no material, unlike classical semiconductor processes that etch silicon wafers. The flexible substrates also allow adaptation to curved surfaces.
Hearing Implants, Retinas, and Movement Therapy
The most obvious application areas lie in neuroprosthetics. Cochlear implants, which today stimulate hearing nerves with electrical pulses, could deliver more natural sound perception with more precise signal patterns. Retinal prostheses for blind patients and interfaces for paralyzed limbs are on the same list of potential applications.
The researchers also see a field of application in information technology itself. Neuromorphic chips could perform AI computations with a fraction of today's energy requirements, which would be particularly relevant for mobile and embedded systems.
Next Steps: From Brain Slices to Implants
The path from mouse brain slices in a laboratory to clinical implants in humans is long. The next stage will test whether the printed neurons also work in vivo — in a living animal over extended periods. Questions of biocompatibility, long-term stability, and implant size must be resolved before human trials become conceivable. Hersam's group is already working, according to their own account, on integrating the devices into three-dimensional circuit structures.