Microfluidic processor brings us one step closer to a future of squishy DNA computing

'Our hope is that DNA-based CPUs will replace electronic CPUs in the future'

Boffins at the Incheon National University have made what they claim to be a breakthrough in computing: a programmable processor which uses DNA, rather than electronics, to perform its computation.

The Microfluidic Processing Unit (MPU) developed by the team is, it claimed, a step forward in simplifying DNA computing – a process which has traditionally required laborious mixing of DNA strands into a reaction tube by hand. The MPU, by contrast, does everything automatically and programmatically – controlled via a traditional PC or smartphone.

Using a prototype produced via 3D printing, the researchers were able to demonstrate how DNA computing can be used for complex mathematical operations via Boolean logic – turning single-stranded DNA templates into logic gates which pair to input DNA with complementary Watson-Crick sequences and produce an output DNA, the length of which offers a binary true-or-false result.

The prototype MPU is, admittedly, basic, offering only AND, OR, XOR, and NOT operations and requiring a traditional computer to drive it – but the team is confident it has potential, predicting that the MPU will "facilitate the development of complex functional circuits such as arithmetic logical units and neuromorphic circuits."

"Our hope is that DNA-based CPUs will replace electronic CPUs in the future," Youngjun Song PhD, assistant professor at INU and the paper's corresponding author, claimed in a statement provided by the university, "because they consume less power, which will help with global warming.

"DNA-based CPUs also provide a platform for complex calculations like deep learning solutions and mathematical modelling."

With Moore's Law distinctly unwell as the laws of physics and economics bite ever-shrinking feature sizes hard, there's considerable interest in finding alternative ways to build processors. DNA might be one of the more outré solutions, but there are plenty more: room-temperature quantum transistors, carbon nanotubes, magneto-electric spin-orbit (MESO) chips, molybdenum disulphide or graphene-based transistors, or simply better programming techniques rather than new hardware as a means of boosting performance.

The INU team isn't the only one looking at DNA as the material to drive forward a new computing revolution, either: Microsoft and the University of Washington showed off DNA-based digital storage back in 2016, writing 200MB of data to strands of encapsulated synthetic DNA – good, the company claimed, for 2,000 years at 10°C or "millions" if chilled down to -18°C. The technology, in no way inspired by the 1981 William Gibson short story and 1995 film Johnny Mnemonic, has not yet made it to market.

There's a long road ahead before any of the aforementioned technologies, including DNA-based computing, can hope to offer true competition to the humble silicon chip. "We have presented a proof of concept for basic logic gate operation and DNA computing via the DNA-based MPU chip, albeit with limited functionality," the team admitted in the paper's conclusion.

Despite this, Song and colleagues remain confident in the technology's potential. "Future research will focus on a total DNA computing solution," he claimed, "with DNA algorithms and DNA storage systems."

The team's work has been published in the journal ACS Nano under closed-access terms. No roadmap has been provided for commercialisation. ®