Tiny devices promise new horizon for security screening and medical imaging

May 06, 2020

Miniature devices that could be developed into safe, high-resolution imaging technology, with uses such as helping doctors identify potentially deadly cancers and treat them early, have been created in research involving the University of Strathclyde.

The devices use terahertz radiation, which can penetrate through materials such as plastics, wood and skin. This form of radiation, which falls between infrared and microwaves in the electromagnetic spectrum, does not damage living tissues as other forms such as X-rays can.

The devices are made from nanowires 100 times thinner than a human hair. They could be used in new, safe imaging technology with far higher resolution than current ultrasound devices used to detect small tumours.

A team of researchers from Strathclyde's Institute of Photonics, in the University's Department of Physics, developed a highly accurate micro-assembly technique to allow the construction of a 3D lattice of nanowire devices. The team used a specialised 'transfer printing' micro-assembly system to print semiconductor nanowire structures, with nanoscale accuracy, in orthogonal patterns onto metal antenna structures.

The study, published in the journal Science, is the result of a collaboration between Strathclyde, the University of Oxford, and the Australian National University (ANU), based in Canberra.

Professor Martin Dawson, one of Strathclyde's lead researchers on the project, said: "It is very exciting to see this collaborative work with our close colleagues at Oxford and ANU published in a journal as prestigious as Science. We have developed novel capabilities for printing of semiconductor nanostructures and microstructures at Strathclyde over the past few years and, combined with ANU's leading ability to grow semiconductor nanowires and Oxford's advanced light detection concepts this has led to very exciting results.

"It has been a pleasure to partner with our colleagues in this work and we look forward to further leading-edge results from the collaboration."

Dr Antonio Hurtado, a Senior Lecturer in Strathclyde's Institute of Photonics, who is also part of Strathclyde's lead team, said: "Building the THz detection systems was a great challenge that required the development at Strathclyde of extremely precise nanofabrication processes. These permitted us to use the semiconductor nanowires from ANU as 'building blocks' for their sequential integration in the 3D THz detectors designed at Oxford, whilst keeping the nanometric accuracy needed to assemble the systems. This has been a great combination of capability and a fantastic collaboration between the different teams involved in this work."

Other terahertz radiation systems, such as those used in airport security scanners, are based on simple intensity detection. However, improved imaging techniques can be implemented by making use of the fact that terahertz radiation, like all electromagnetic waves, contains polarisation information - the direction of the electromagnetic fields as they propagate through space.

The orientation of the nanowires in the device allows terahertz radiation with different polarisations to be measured independently and given the compact device area, paves the way for future on-chip imaging systems.

University of Strathclyde

Related Nanowires Articles from Brightsurf:

A new, highly sensitive chemical sensor uses protein nanowires
Writing in NanoResearch, a team at UMass Amherst reports that they have developed bioelectronic ammonia gas sensors that are among the most sensitive ever made.

Giving nanowires a DNA-like twist
Argonne National Laboratory played a critical role in the discovery of a DNA-like twisted crystal structure created with a germanium sulfide nanowire, also known as a 'van der Waals material.' Researchers can tailor these nanowires in many different ways -- twist periods from two to twenty micrometers, lengths up to hundreds of micrometers, and radial dimensions from several hundred nanometers to about ten micrometers.

Shell increases versatility of nanowires
Nanowires promise to make LEDs more colorful and solar cells more efficient, in addition to speeding up computers.

Scientists synthesize new nanowires to improve high-speed communication
Scientists from the Institute of Process Engineering, City University of Hong Kong and their collaborators synthesized highly crystalline ternary In0.28Ga0.72Sb nanowires to demonstrate high carrier mobility and fast IR response.

Dose of vitamin C helps gold nanowires grow
Rice University scientists discover a method to turn stubby gold nanorods into gold nanowires of impressive length.

Silver nanowires promise more comfortable smart textiles
In a paper to be published in the forthcoming issue in NANO, researchers from the Nanjing University of Posts and Telecommunications have developed a simple, scalable and low-cost capillary-driven self-assembly method to prepare flexible and stretchable conductive fibers that have applications in wearable electronics and smart fabrics.

Artificial synapses made from nanowires
Scientists from J├╝lich together with colleagues from Aachen and Turin have produced a memristive element made from nanowires that functions in much the same way as a biological nerve cell.

Nanowires could make lithium ion batteries safer
From cell phones and laptops to electric vehicles, lithium-ion batteries are the power source that fuels everyday life.

Scientists have a new way to gauge the growth of nanowires
In a new study, researchers from the US Department of Energy's Argonne and Brookhaven National Laboratories observed the formation of two kinds of defects in individual nanowires, which are smaller in diameter than a human hair.

Cleaning nanowires to get out more light
A simple chemical surface treatment improves the performance of nanowire ultraviolet light-emitting diodes.

Read More: Nanowires News and Nanowires Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.