🧬 Harvard Built a Silicon Chip That Can Write DNA Using Electricity and Water
Writing custom DNA has barely changed in decades. Today’s DNA synthesis relies on phosphoramidite chemistry—a highly effective but solvent-intensive process that depends on hazardous chemicals and specialized manufacturing facilities.
Researchers at Harvard have now demonstrated a completely different approach: parallel enzymatic DNA synthesis on a semiconductor chip, controlled simply by electricity in water.
The CMOS chip contains 64 programmable synthesis sites, each surrounded by two concentric ring electrodes. When current flows through the inner ring, it generates protons that create a tiny acidic region—exactly what’s needed to remove the temporary blocking group from a growing DNA strand. At the same time, the outer ring consumes escaping protons, preventing neighboring reactions from interfering with one another.
Using this approach, the team synthesized 64 different DNA sequences, each 38–39 nucleotides long, entirely in an aqueous enzymatic process. Previous demonstrations of parallel enzymatic DNA synthesis were limited to roughly a dozen sequences, making this the largest demonstration of its kind so far.
The hardware has an unusual history. It was originally developed for recording electrical activity from thousands of neurons. The researchers later realized that the same ability to precisely control microscopic electrical currents could also be used to control chemical reactions needed for DNA synthesis.
Key points:
• 64 unique DNA sequences synthesized in parallel • Water-based enzymatic process instead of traditional solvent-heavy chemistry • Precise local pH control using dual concentric electrodes • DNA strands up to 39 nucleotides long • Demonstrated storage of a 169-byte text message in the synthesized DNA
The technology is still at an early stage. DNA strands of 39 nucleotides are far shorter than real genes, which typically contain thousands of bases. According to the researchers, the main limitation is now the chemistry used to remove temporary protecting groups—not the chip itself—suggesting that future advances may come from improved chemistry rather than new electronics.
If the method can be scaled, it could eventually make DNA manufacturing cleaner, cheaper, and more accessible for synthetic biology, diagnostics, gene therapies, and even DNA-based data storage, one of the highest-density storage media ever proposed.
📄 Nature Electronics: https://www.nature.com/articles/s41928-026-01662-9 🏛 Harvard SEAS: https://seas.harvard.edu/news/making-dna-semiconductor-chip
#DNA #SyntheticBiology #Biotechnology #Semiconductors #DataStorage