Scientists have designed an affordable microscopic imaging device that is small enough to fit on the lens of a smartphone camera, potentially making the detection of diseases on mobile more economical and accessible.
Researchers from the University of Melbourne and the Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems (TMOS) have published research in ACS Photonics that demonstrates how metasurfaces, which are only a few hundred nanometres thick — roughly 350 times thinner than the thickness of a human hair — can help miniaturize phase-imaging technology.
They are small enough to fit on the lens of a smartphone or other small camera.
Optical microscope technology is frequently used to analyze changes in biological cells to diagnose diseases. At present, these techniques of investigation entail staining cells with chemicals in a laboratory setting and utilizing specialized “phase-imaging” microscopes.
They make previously unseen elements of a biological cell visible, allowing for disease identification at an early stage. Phase-imaging microscopes, however, are big and expensive, positioning them out of reach of remote medical practices.
This innovative technique might one day lead to disease detection at home, where the patient can obtain their samples through saliva or a pinprick of blood, and then send an image to a laboratory anywhere in the world. Analysis and diagnosis of the disease will then be done in the lab.
According to lead researcher Dr. Lukas Wesemann from the University of Melbourne, the metasurfaces can alter the light traveling through them to make previously unseen elements of things like live biological cells visible.
We manufactured our metasurface with an array of tiny rods—nanorods—on a flat surface, arranged in such a way as to turn an invisible property of light, called its ‘phase’, into a normal image visible to the human eye, or conventional cameras. These phase-imaging metasurfaces create high contrast, pseudo-3D images without the need for computer post-processing.
Dr. Lukas Wesemann, Lead Researcher, University of Melbourne
Wesemann adds, “Making medical diagnostic devices smaller, cheaper and more portable will help disadvantaged regions gain access to healthcare that is currently only available to first world countries.”
Ann Roberts, co-author and TMOS Chief Investigator at the University of Melbourne, described the study as an exciting breakthrough in the field of phase imaging.
Roberts concludes, “It’s just the tip of the iceberg in terms of how metasurfaces will completely reimagine conventional optics and lead to a new generation of miniaturized devices.”
Wesemann, L., et al. Real-Time Phase Imaging with an Asymmetric Transfer Function Metasurface. ACS Photonics. doi.org/10.1021/acsphotonics.2c00346.