Engineers are printing tiny artificial neurons that can “talk” to mouse brain cells, a development that could pave the way for innovations in computing and medicine.
The study, published April 15 in the journal Nature Nanotechnology, adds to a growing field aimed at building computers that mimic the inner workings of the brain.
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“We’re trying to mimic the brain as closely as possible,” says study co-author Mark Hartham, professor of materials science and engineering at Northwestern University. “What motivates us is to come up with an alternative to traditional digital computing that processes large amounts of data in a more energy-efficient way,” he told Live Science.
The research could also usher in new brain-computer interfaces that allow electronic devices to be controlled by brain activity. Brain-computer interfaces can be used, for example, to control prosthetic limbs or assistive communication devices.
Neuromorphic computers are designed to emulate the brain, so they should be well-suited to interacting with brain tissue. Additionally, some scientists have suggested that artificial neurons may be able to replace damaged nerve cells or restore brain function lost in degenerative diseases such as Alzheimer’s disease.
Put your brain on a chip
Traditional silicon chips cannot be used to recreate brain tissue. Silicon chips are rigid and built with repeating transistors arranged in a two-dimensional structure. They have fixed connections that cannot evolve.
It’s a far cry from the brain’s delicate infrastructure. Brain cells are physically flexible and communicate in a 3D matrix that changes depending on location and changes over time. Connections between neurons grow stronger with continued use, but can weaken if you don’t use them enough. All of these properties are necessary to create complex processors that constantly understand the complex world around us.
Because of this conflict between the brain and the machine, most brain-computer interfaces cannot be inserted seamlessly into the brain. Instead, it relies on relatively coarse pulses to communicate with neurons. Creating efficient artificial neurons means finding materials that feel and behave like neurons, in that they mimic neurons’ firing patterns and adjust their signals as needed.
Artificial neurons designed before the new research tend to use either soft organic materials, such as gels or tissues, or hard metal oxides, which can allow electrical or chemical signals to pass through. Each approach has drawbacks. Soft material spike patterns tend to be too slow, while hard material spike patterns tend to be too fast, Hersam explained.
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To better replicate neurons, Hartham and his team used a printing ink mixed with molybdenum disulfide, an inorganic compound that acts as a semiconductor, and tiny flakes of graphene, an electrical conductor. The ink is printed onto a flexible polymer substrate.
All kinds of biologically mimicking spike responses can be achieved.
Mark Hartham, Professor of Materials Science and Engineering, Northwestern University
Historically, such substrates have been considered obstacles because the polymer impedes electrical current flow. But this could be a boon for artificial neurons, as Hersam and his colleagues discovered that polymers can be manipulated to control how electricity flows through brain cells created in the lab.
“The key innovation was this partial degradation of the polymer,” Hersam said.
By carefully adjusting how polymers heat and decompose, engineers can create tiny filaments of energy. Rather than steadily increasing, the current flowing through the neuron increases and then decreases, allowing for sudden releases of energy similar to neuron spikes. This behavior is called “snapback negative differential resistance.”
By adjusting the device’s parameters, the team was also able to generate more complex signal patterns, such as a series of spikes spaced apart in time or sudden spikes. “We can do all kinds of spike reactions that mimic biology,” Hersam said.
To prove this, scientists placed artificial neurons next to slices of mouse brains in an experimental dish. They found that the mice’s neurons fired at the same pace as the artificial neurons, suggesting that the tissue could decipher artificial signals as if they were born from real tissue.
Artificial neuron of the future
Timothy Levy, a professor of bioelectronics at France’s University of Bordeaux who studies artificial neurons, praised this new type of artificial neuron, noting that it “matches the normal frequency of neurons.”
Levi, who was not involved in the research, said the study adds to a series of recent studies showing that artificial neurons can communicate with biological neurons. These developments have been unfolding in parallel with many advances that improve how artificial neurons are built, interconnected and programmed, Levi said.
However, he stressed that artificial neurons are still far from fully communicating with biological neurons in a meaningful way. “We can control it in the short term, but we can’t control it in the long term yet,” so it’s not yet suitable for permanent addition to the human brain, for example, he said.
Levi and Hersam pointed out that there is still much work to be done to understand how the brain works so that it can be faithfully reproduced in computers. Moreover, artificial neurons alone are not enough. We need to connect artificial neurons with artificial synapses.
“The problem at the frontier is that we have a series of devices that mimic different elements of the brain, but we need to integrate them into fully functional circuits,” Hartham said.
Hadke, SS, Klingler, CN, Brown, ST, et al. Printed MoS2 memristive nanosheet networks for spiking neurons with multi-order complexity. Natural nanotechnology. (2026). https://doi.org/10.1038/s41565-026-02149-6
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