Scientists are experimenting with living human brain cells to create a new kind of computer, marking a breakthrough in biocomputing or “wetware.” The Swiss start-up FinalSpark is leading the effort, using clusters of neurons called organoids to perform simple computational tasks.
Co-founder Dr. Fred Jordan explained, “Instead of trying to mimic the brain with silicon, let’s use the real thing.” These organoids are grown from human skin cells, reprogrammed into stem cells, and developed into neurons. Each cluster is roughly the size of a fruit fly’s brain and contains about 10,000 neurons — a tiny fraction of the 100 billion neurons in a human brain — but they already demonstrate basic learning behaviors and responses to electrical stimulation.
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How living computers operate
In the lab, organoids are kept in a nutrient-rich solution and connected to electrodes that transmit electrical pulses. These pulses stimulate the neurons, which respond with activity spikes — a biological analogue of binary ones and zeroes in digital computing.
BBC science editor Zoe Kleinman described watching a keyboard press trigger activity in the organoid. “You press a key, and you can just about see a little jump of activity on a screen in response,” she noted.
Researchers have also experimented with reinforcing neural activity using dopamine, the brain’s natural reward chemical. This mimics how humans learn through motivation, offering a biological pathway for training living processors. Biological neurons are approximately one million times more energy-efficient than artificial ones, highlighting wetware’s potential to reduce AI’s growing energy demands.
Challenges of living computing
Maintaining organoids is delicate. Unlike traditional silicon processors, they cannot be rebooted after dying. FinalSpark’s organoids currently survive up to four months. Professor Simon Schultz of Imperial College London explained, “Organoids don’t have blood vessels. We don’t yet know how to make them properly, so this is the biggest ongoing challenge.”
Before dying, organoids sometimes display a sudden surge of activity, similar to the final electrical spike observed in human brains at death, according to Jordan.
Global collaboration and research potential
FinalSpark has already partnered with 10 universities worldwide, offering live feeds of neural activity on its website. Other researchers are also exploring biocomputing: in 2022, Australia’s Cortical Labs trained neurons to play Pong, and Johns Hopkins University uses mini-brains to model diseases like Alzheimer’s and autism.
Experts caution that wetware will not replace silicon-based computing soon. Dr. Lena Smirnova of Johns Hopkins said, “Biocomputing should complement — not replace — silicon AI, while advancing disease modeling and reducing animal use.”
Ethics and future outlook
Ethical considerations remain central. FinalSpark collaborates with ethicists to ensure that organoids, which lack pain receptors and complex structures, cannot experience consciousness.
While still in its infancy, biocomputing could redefine computing efficiency, provide new insights into the human brain, and accelerate neurological research. The technology represents a new frontier where biology and computation converge, hinting at a future where living processors work alongside traditional silicon chips.
