Silicon chips have powered computers for many years. Now scientists are using them in biology. A new chip can not only read signals from nerves, it can also build DNA.
Cleaner DNA Production
Making custom DNA usually needs harsh chemicals that can be dangerous. The Harvard team chose a gentler method that uses water and enzymes, just like cells do. Their chip can create 64 different DNA strings at the same time, each up to 39 building blocks long.
How the Chip Writes DNA
DNA is built one piece at a time. After each piece is added, a tiny blocker stops the chain from growing. To add the next piece, the blocker must be removed with acid (low pH) in water.
The chip has 64 tiny spots. Each spot has two ring‑shaped electrodes around a DNA starter molecule. When the inner electrode sends a small electric current, it creates protons that lower the pH right at that spot, removing the blocker so the next DNA piece can attach. The outer electrode pulls the protons away, keeping the acidic area confined.
By repeating this cycle, the chip builds 64 unique DNA sequences side by side.
From Brain Sensors to DNA Builders
The chip was first made to record electrical activity from many neurons. Jeffrey Abbott, a former graduate student, redesigned the surface electrodes. He realized the same precise current control could shape the chemical environment needed for DNA synthesis.
Future Uses: Storing Data in DNA
The researchers showed that the 64 DNA strands could hold a short 169‑byte text. While storing large amounts of data in DNA still needs bigger production, water‑based enzymatic synthesis could become attractive because it uses fewer harmful solvents.
What Limits the Chip?
When the team tried to pack the synthesis spots closer together, the chemistry became the bottleneck. Low pH creates intermediate molecules that can drift to neighboring spots, mixing the reactions even though the pH stays localized.
Collaboration and Support
The project brought together Harvard, the Broad Institute, DNA Script, and POSTECH. The work is protected by patents filed by Harvard’s Office of Technology Development. Funding came from several agencies, including the Office of the Director of National Intelligence and Samsung’s research program.