According to research published in Nature Nanotechnology, scientists have produced the first functional nanoscale electromotor in history. The scientific team created a DNA-engineered turbine that runs on hydrodynamic flow within a nanopore—a hole in a solid-state silicon nitride membrane that is only a nanometer in size.
Scientists have created the world’s first working nanoscale electomotor. The science team designed a turbine engineered from DNA that is powered by hydrodynamic flow inside a nanopore, a nanometer-sized hole in a membrane of solid-state silicon nitride. The tiny motor could help spark research into future applications such as building molecular factories or even medical probes of molecules inside the bloodstream. Image Credit: TACC
The small motor could be a catalyst for future research into applications like creating molecular factories to produce valuable chemicals or medical probes that use molecules in the bloodstream to identify diseases like cancer.
Common macroscopic machines become inefficient at the nanoscale. We have to develop new principles and physical mechanisms to realize electromotors at the very, very small scales.
Aleksei Aksimentiev, Study Co-Author and Professor, University of Illinois at Urbana-Champagne
Hendrik Dietz of the Technical University of Munich and Cees Dekker of the Delft University of Technology carried out the experimental work on the small motor.
Dietz is a world authority in origami DNA. The small motor’s turbine, made of three blades with a total length of around 72 base pairs and thirty double-stranded DNA helices fashioned onto an axle, was created by his group by manipulating DNA molecules.
Decker’s laboratory proved that the turbine could revolve when applied to an electric field. Using a system of five million atoms, Aksimentiev’s group performed all-atom molecular dynamics simulations to characterize the physical events involved in the operation of the motor.
The system was the simplest model of the experiment that might produce significant findings.
Aksimentiev added, “It was one of the largest ever simulated from the DNA origami perspective.”
Mission Impossible to Mission Possible
Aksimentiev received a Leadership Resource Allocation from the Texas Advanced Computing Center (TACC) to support his research on mesoscale biological systems on Frontera, the nation’s best academic supercomputer, which is financed by the National Science Foundation (NSF).
“Frontera was instrumental in this DNA nanoturbine work. We obtained microsecond simulation trajectories in two to three weeks instead of waiting for a year or more on smaller computing systems. The big simulations were done on Frontera using about a quarter of the machine—over 2,000 nodes; However, it is not just the hardware, but also the interaction with TACC staff. It’s extremely important to make the best use of the resources once we have the opportunity,” Aksimentiev stated.
Aksimentiev additionally received supercomputer allocations for this study from the NSF-funded Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) on Expanse of the San Diego Supercomputer Center and Purdue University’s Anvil.
“We had up to 100 different nanomotor systems to simulate. We had to run them for different conditions and in a speedy manner, which the ACCESS supercomputers assisted with perfectly. Many thanks to the NSF for their support—we would not be able to do the science that we do without these systems,” Aksimentiev added.
DNA as a Building Block
The success of the operating DNA nanoturbine draws on a prior study that also utilized Frontera and ACCESS supercomputers. According to the study, a single DNA helix is the smallest electromotor possible, capable of rotating at up to a billion revolutions per minute.
Aksimentiev claims that DNA has emerged as a nanoscale building material.
The way DNA base pair is a very powerful programming tool. We can program geometrical, three-dimensional objects from DNA using the Cadnano software just by programming the sequence of letters that make up the rungs of the double helix.
Aleksei Aksimentiev, Study Co-Author and Professor, University of Illinois at Urbana-Champagne
Another argument for adopting DNA as a building block is that it has a negative charge, which is required to create an electromotor.
He further explained., “We wanted to reproduce one of the most spectacular biological machines—ATP synthase, which is driven by electric field. We chose to do our motor with DNA.”
He added, “This new work is the first nanoscale motor where we can control the rotational speed and direction.”
It is accomplished by varying the electric field across the solid-state nanopore membrane and the salt concentrations in the fluid around the rotor.
He stated, “In the future, we might be able to synthesize a molecule using the new nanoscale electromotor, or we can use it to as an element of a bigger molecular factory, where things are moved around. Or we could imagine it as a vehicle for soft propulsion, where synthetic systems can go into a blood stream and probe molecules or cells one at a time.”
Aksimentiev concluded, “We were able to accomplish this because of supercomputers. Supercomputers are becoming more and more indispensable as the complexity of the systems that we build increases. They are the computational microscopes, which at ultimate resolutions can see the motion of individual atoms and how that is coupled to a bigger system.”
Journal Reference:
Shi, X., et. al. (2024) A DNA turbine powered by a transmembrane potential across a nanopore. Nature Nanotechnology. doi:10.1038/s41565-023-01527-8.