From folded DNA strands to miniature robots and nano-sized computing components, these innovations show how the future of Australian engineering might be fun-size.
In 2016, the Nobel Foundation recognised three European researchers for a truly tiny accomplishment. Jean-Pierre Sauvage, J Fraser Stoddart and Bernard Feringa received the Nobel Prize for Chemistry in recognition of their work designing machines mere nanometres in size, with effects that were measured at a scale of fractions of a billionth of a metre.
These molecular devices could be used as switches, extend or contract like muscles, and power themselves forward via light-driven propellers. And while their work had little practical application at the time they were awarded the Nobel, it contained immense potential.
“In terms of development,” the Royal Swedish Academy of Sciences said, “the molecular motor is at the same stage as the electric motor was in the 1830s, when scientists displayed various spinning cranks and wheels, unaware that they would lead to electric trains, washing machines, fans and food processors.”
Stoddart would go on to take a position at the University of NSW, leading research into his New Chemistry Initiative – or “molecular Meccano”, as he sometimes referred to it – before his death in 2024.
It’s just one example of the big impact that even the tiniest technology can have – and it’s far from the only one. In this article, create puts five of Australia’s smallest machines under the microscope.
1. The voxel
Using what they describe as “DNA origami”, researchers from the University of Sydney have developed a modular system of custom-designed and programmable synthetic molecular nanostructures. Measuring just hundreds of nanometres in size, these three-dimensional structures dubbed “voxels” use DNA strands adhered to their exterior to bind with other strands like miniscule Velcro pads.
“We’ve created a new class of nanomaterials with adjustable properties, enabling diverse applications – from adaptive materials that change optical properties in response to the environment to autonomous nanorobots designed to seek out and destroy cancer cells,” said Dr Minh Tri Luu of the University of Sydney’s Nano Institute.
According to the researchers, the nanorobots that use the technology have potential application in such areas as synthetic biology, nanomedicine and materials science.
2. Making waves
The “world’s smallest wave tank” is just 100 microns long and its contents consist of a thin film of superfluid helium. Hosted at the University of Queensland’s Queensland Quantum Optics Lab, the hair-thin device helps researchers model water waves that exhibit nonlinear behaviour, such as solitons, rogue waves and tsunamis – work that usually requires large tanks.
“These facilities only reach a fraction of the complexity of waves found in nature,” said UQ Professor Warwick Bowen. “Our miniature device amplifies the nonlinearities that drive these complex behaviours by more than 100,000 times. Being able to study these effects at chip scale – with quantum-level precision – could transform how we understand and model them.”
The superfluid helium’s quantum properties allow it to flow with minimal resistance across the surface of a silicon chip. Researchers are able to precisely control the fluid’s effective gravity, dispersion and nonlinearity, and generate waves using a laser.
3. One giant leap for computing
Engineers are pushing the boundaries of nano-scale machines, but the subatomic distances involved with quantum computing are as small as it gets. The qubit – the basic unit of information in quantum computing – uses the physics of quantum mechanics to store information outside of the binary system of ones and zeroes.
A number of Australian organisations, including the University of Sydney, the University of New South Wales and the University of Queensland, are working to refine the technology, but the challenges remain significant. The University of Queensland’s $10.8 million National Quantum Computing Testbed, for instance, hosts a five-qubit quantum computer with processors that must be cooled to minus 273 degrees Celsius to protect them from electrical noise interference.
Previous advances have come when UNSW engineers found a technique to control the nucleus of a single atom and an approach to manufacture reliable chips at a utility scale. Researchers are now seeking to minimise errors in the qubits without disrupting the information they contain.
4. Light matters
Just as subatomic particles hold promise for the future of computing, so do the properties of light. Nonlinear optics is a field that uses visible light or infrared radiation to perform computing work, leading to faster speeds and smaller components.
Researchers at the Australian National University, for instance, have developed nanoparticles made of silicon and silicon nitrite that treat light waves differently depending on the direction they are travelling. The researchers were able to produce images by arranging nanoparticles that impose different conditions on the light into different configurations.
The ANU’s Sergey Kruk told the ABC the research may be “a first convincing step towards establishing a very sophisticated traffic control of beams of light”, comparable to those used in traditional electric circuits.
“At this stage of technological development, we’ve gotten incredibly good at controlling electrical currents, and we are not as good at controlling beams of light,” he said.
5. Liquid metal robots
Engineers at the University of Queensland have developed a 4D-printing technique that allows them to create soft robotic devices using spherical liquid metal nanoparticles. Working with the Australian National Fabrication Facility allowed the researchers to manufacture robots with a size under 1 mm, which then change shape when exposed to light, heat or water.
The robots, which can return to their original shape after manipulating objects up to five times their own weight, could one day see use in the aeronautics or medical device sectors.
“This is a new era for robotics applications and a gamechanger for additive manufacturing,” said the University of Queensland’s Dr Liwen Zhang.
“Our method allows us to produce smart liquid metals that can be customised, shaped and prompted to change over time without needing wires or circuits.”
