![The Chip That Writes DNA](https://cdn.slatesource.com/5/1/7/517ec53e-1685-4799-b480-f0597cc8c7b1.webp) # The Chip That Writes DNA - [Made in Slatesource](https://slatesource.com/@steph/the-chip-that-writes-dna) - By [Steph](https://slatesource.com/@steph) - Created on Jul 31, 2026 ## What just happenedhappened at HarvardHarvard SEASSEAS EngineersEngineers at HarvardHarvard JohnJohn A. PaulsonPaulson SchoolSchool of EngineeringEngineering and AppliedApplied SciencesSciences have builtbuilt a siliconsilicon chipchip that writeswrites DNADNA sequencessequences usingusing electricityelectricity and waterwater, replacingreplacing the toxictoxic organicorganic solventssolvents that have underpinnedunderpinned DNADNA synthesissynthesis sincesince 19811981. The workwork was publishedpublished in NatureNature ElectronicsElectronics on 17 JuneJune 20262026 by DonheeDonhee Ham'sHam's lablab, in collaborationcollaboration with the BroadBroad InstituteInstitute, DNADNA ScriptScript, and POSTECHPOSTECH. The chipchip synthesisedsynthesised 64 distinctdistinct DNADNA sequencessequences in parallelparallel and encodedencoded 169169 bytesbytes of texttext into moleculesmolecules, settingsetting a newnew benchmarkbenchmark for enzymaticenzymatic DNADNA synthesissynthesis. Institution Harvard SEAS and the Broad Institute of MIT and Harvard Journal Nature Electronics, 17 June 2026 Sequences synthesised in parallel 64 (previous enzymatic record: 12) Data encoded 169 bytes of text written into synthesised DNA Chip architecture 256 ring-electrode pairs on a CMOS chip Solvent used Water (replacing hazardous organic solvents) Lead researcher Professor Donhee Ham, Harvard SEAS ## How it actuallyactually worksworks TraditionalTraditional DNADNA synthesissynthesis, inventedinvented by MarvinMarvin CaruthersCaruthers in 19811981, buildsbuilds strandsstrands nucleotidenucleotide by nucleotidenucleotide usingusing phosphoramiditephosphoramidite chemistrychemistry: a seriesseries of organicorganic solventsolvent washeswashes that couplecouple eacheach newnew letterletter to the growinggrowing strandstrand. It worksworks wellwell at scalescale but requiresrequires hazardoushazardous reagentsreagents, largelarge facilitiesfacilities, and significantsignificant chemicalchemical wastewaste. The approachapproach has not changedchanged in fourfour decadesdecades. The HarvardHarvard chipchip worksworks entirelyentirely differentlydifferently. The CMOSCMOS semiconductorsemiconductor carriescarries 256256 ring-electrodering-electrode pairspairs. At eacheach synthesissynthesis sitesite, twotwo concentricconcentric ringsrings sitsit aroundaround an anchoredanchored DNADNA strandstrand. When the innerinner electrodeelectrode passespasses a smallsmall currentcurrent throughthrough waterwater, it generatesgenerates protonsprotons, loweringlowering the locallocal pH. That acidicacidic pocketpocket activatesactivates an enzymeenzyme, a DNADNA polymerasepolymerase, whichwhich snapssnaps the nextnext nucleotidenucleotide ontoonto the growinggrowing strandstrand. The outerouter ringring simultaneouslysimultaneously drawsdraws currentcurrent to mopmop up straystray protonsprotons, preventingpreventing the acidacid zonezone from driftingdrifting to neighbouringneighbouring sitessites and corruptingcorrupting their sequencessequences. CyclingCycling throughthrough these stepssteps at selectedselected sitessites buildsbuilds up > A defining feature of the chip was precision current injection, which we used to permeabilise neuronal membranes for intracellular access. At a certain point, we wondered whether that same current control could be redirected from cells to molecules. It wo Seven things this chip could change 0% \- DNA data storage at scale. DNA can pack an estimated 215 petabytes into one gram. The chip encoded 169 bytes. Scaling parallel synthesis beyond 64 sequences opens a credible path to chip-scale storage: dense, durable and readable centuries from now. \- Portable synthesis devices. Because the chip uses water and standard CMOS fabrication, it works with existing semiconductor manufacturing. That means smaller, safer synthesis devices outside central facilities: a hospital lab or a field diagnostic unit. \- Synthetic biology on demand. Gene circuits, biological sensors, and engineered organisms all require custom DNA sequences. Faster, cheaper, water-based synthesis accelerates the design-build-test cycle that drives synthetic biology. \- CRISPR guide RNA production. Every CRISPR experiment needs guide RNA molecules that are themselves written from a DNA template. More agile synthesis means more rapid genome-editing research and clinical applications. \- Cancer diagnostics. Tumour profiling requires synthesising panels of DNA probes matched to patient mutations. Localised, fast synthesis improves the speed and cost of personalised cancer diagnostics. \- Pandemic preparedness. Rapid synthesis of viral genome fragments underpins diagnostic test design and vaccine development. A chip-scale platform could compress the timeline from outbreak identification to test availability. \- Environmental monitoring. Synthetic DNA probes designed to bind specific pathogens or pollutants can be deployed in water and air monitoring systems. Cheaper synthesis makes denser, more widespread deployment practical. > DNA data storage asks DNA synthesis to operate at a scale far beyond today's needs. That is why enzymatic synthesis in water can matter. If far more than 64 sequences can be synthesised in parallel, it could offer an environmentally friendly route toward ## The honesthonest bottleneckbottleneck The CMOSCMOS chipchip itselfitself is not the limitationlimitation. Its 256256 electrodeelectrode pairspairs alreadyalready outnumberoutnumber the 64 sequencessequences synthesisedsynthesised in this paperpaper. The constraintconstraint is chemicalchemical. BetweenBetween eacheach nucleotidenucleotide additionaddition, a temporarytemporary blockingblocking groupgroup mustmust be removedremoved in a deprotectiondeprotection stepstep. The intermediateintermediate moleculesmolecules releasedreleased duringduring deprotectiondeprotection driftdrift to neighbouringneighbouring sitessites and interfereinterfere with their synthesissynthesis, limitinglimiting how denselydensely sitessites can be packedpacked and how longlong the sequencessequences can growgrow. The team'steam's currentcurrent recordrecord is 39 nucleotidesnucleotides perper strandstrand. Co-firstCo-first authorauthor HanHan SaeSae JungJung putput it plainlyplainly: the chipchip did what was askedasked of it; the limitationlimitation camecame from the chemistrychemistry, not the siliconsilicon. The nextnext engineeringengineering challengechallenge is developingdeveloping a moremore spatiallyspatially confinedconfined, directdirect acid-drivenacid-driven deprotectiondeprotection chemistrychemistry that can keepkeep pacepace with the chip'schip's precisionprecision. That is a hardhard problemproblem, but it is a defineddefined oneone, and the fieldfield nownow has a clearclear targettarget. The paper, "Parallel enzymatic DNA synthesis using a semiconductor chip," appears in Nature Electronics, June 2026 (DOI: 10.1038/s41928-026-01662-9). Funding came from Harvard, the Broad Institute, the US National Science Foundation, and DNA Script. This is academic research, not a commercial product. Replication and independent validation by other groups is the next step before applications. [Harvard SEAS: Making DNA on a semiconductor chip](https://seas.harvard.edu/news/making-dna-semiconductor-chip?utm_source=slatesource) [Phys.org: Semiconductor chip writes 64 DNA sequences in water](https://phys.org/news/2026-06-semiconductor-chip-dna-sequences-enzymatic.html?utm_source=slatesource)