Scientists in South Korea have created an artificial synapse that works with extremely low energy, remembers information for an unusually long time, and naturally breaks down after use.
The breakthrough, reported in Nature Communications, could help pave the way for environmentally friendly brain-inspired electronics that leave no lasting waste behind.
The research team, affiliated with Ulsan National Institute of Science and Technology (UNIST), set out to tackle two growing problems in modern electronics: high energy consumption and electronic waste.
As devices become smaller and more widespread, discarded electronics are piling up faster than they can be safely recycled.
Neuromorphic technologies, which imitate how the human brain processes information, promise major gains in efficiency, but they are usually built from materials that persist in the environment.
Led by Hyunhyub Ko, the team designed a fully biodegradable artificial synapse using materials sourced from nature.
These include cellulose from plant stems, chitosan derived from shells, and other bio-based polymers. Together, they form a tiny layered device that functions much like a real synapse in the brain.
The artificial synapse is built like a microscopic sandwich. Inside it are ion-active layers separated by an ion-binding layer.
When a small electrical signal is applied, sodium ions move through the structure, similar to how neurotransmitters travel between neurons.
Some of these ions remain trapped at the internal boundaries even after the signal stops. This allows the device to “remember” past signals and respond differently to future ones.
Thanks to this mechanism, the synapse can show both short-term and long-term memory behaviors. Most impressively, it can retain information for nearly 6,000 seconds, or about 100 minutes. This is the longest memory retention ever reported for a fully biodegradable artificial synapse.
The device is also remarkably energy efficient. Each signal consumes just 0.85 femtojoules of energy, which is even lower than what biological synapses in the human brain typically use. This makes it especially attractive for low-power computing systems that need to operate for long periods without frequent recharging.
Environmental safety is another major strength. When placed in soil, the key components of the device fully degrade within about 16 days, leaving no harmful residues behind. This opens the door to electronics designed to work temporarily and then vanish once their job is done.
To demonstrate its real-world potential, the researchers connected the synapse to a simple robotic system. When the robot sensed heat, the artificial synapse amplified the signal and triggered a quick withdrawal response, mimicking a natural reflex.
The team believes this technology could lead to sustainable robots, sensors, and medical devices that interact with the environment intelligently and then safely disappear, marking an important step toward greener electronics inspired by the human brain.
