Conventional Glass Fibers Used to Create High-Performance Diamond Sensors

Karen Cunningham, an Adelaide glass blower, used diamond and glass to make art. However, she never expected that it would lead to the creation of a new type of hybrid material.

At present, a consortium of researchers, which includes RMIT University and the University of Adelaide, has used this technology to develop a new category of quantum sensors. Reported in the APL Materials journal, the study shows how traditional glass fibers can be used to develop high-performance diamond sensors.

The researchers embedded micron-scale diamond particles inside the cross section of a silicate glass fiber, thus demonstrating the use of a rugged fiber material that can sense magnetic fields.

According to Dr Dongbi Bai, lead author of the study from the RMIT School of Science, it was a stimulating achievement that paves the way to several applications in mining, underwater monitoring, and much more.

This allows us to make cheap quantum sensor networks that are able to monitor changes in magnetic field, with many useful applications and the answers to questions we haven’t thought of yet.

Dr Dongbi Bai, Study Lead Author, School of Science, RMIT University

In the area of quantum magnetic field sensing, diamond is one of the pioneering technologies, finding applications as wide-ranging as mineral exploration, brain scanning, and navigation.

However, it is necessary to observe diamond particles using high-end microscopes, which are not suitable to use in the field or over an extended period.

According to Heike Ebendorff-Heidepriem, Deputy Director of the Institute for Photonics and Advanced Sensing at the University of Adelaide, the researchers had been making efforts to overcome this problem for around 10 years.

But because diamond burns at high temperatures, we’ve been limited in the glasses that we can use.

Heike Ebendorff-Heidepriem, Deputy Director, Institute for Photonics and Advanced Sensing, University of Adelaide

Although the researchers have learned much from the so-called “soft glasses,” these are non-standard and not so good as traditional silica fibers (for example, those used in the National Broadband Network) at guiding light.

From Art to Science

Glass artist Karen Cunningham plays a crucial role in this respect. She used nanoparticles to develop art to illustrate the movement of light through glass and was spellbound by the diamonds used by Heike and her collaborators in her study.

“We gave Karen some of our larger diamonds to see how they worked,” stated Professor Brant Gibson, from the RMIT School of Science.

The diameter of the diamonds that he gave Karen was about 1 μm—50 times smaller compared to the width of a strand of human hair.

“For most of our work, these diamonds are just too big, so we use them mainly for testing,” he added.

Surprisingly, the diamonds were found to survive Karen’s glass blowing, and formed part of her exhibition at JamFactory in Adelaide, in 2017.

“For us, it was the lightbulb moment and we knew we could make diamond sensors in more conventional glass fibres,” explained Heike.

Three more years of testing and fabrication were need to translate Karen’s art into prototype sensors, noted Dr Dongbi Bai.

It always takes hard work to go from the idea to the product, but I’m so excited by what we’ve achieved, and even more excited by where this new quantum sensor can take us.

Heike Ebendorff-Heidepriem, Deputy Director, Institute for Photonics and Advanced Sensing, University of Adelaide

The research was financially supported by the Australian Research Council and the Defence Science and Technology Group through the Next Generation Technology Fund.

The consortium includes researchers from RMIT University, University of Adelaide, University of Melbourne, University of South Australia, and the Defence Science and Technology Group.

Journal Reference:

Bai, D., et al. (2020) Fluorescent diamond microparticle doped glass fiber for magnetic field sensing. APL Materials. doi.org/10.1063/5.0013473.