3D-Printed Microlenses for Long-Distance Spectroscopy

3D-printed microlenses. (Image courtesy of the University of Warsaw.)

Most people have used a microscope at some point in their lives for either work or school. We learn that microscopy uses specialized lenses to enhance the visibility of small particulate matter from organisms and tissue, among other things.

Spectroscopy is a bit different, in that it uses electromagnetic radiation to determine the transmittance or absorbance of a sample, lending clues to the sample’s structure, molecular composition, and other characteristics.

A standard spectroscopic microscope must be placed at a very small distance from the sample. This can lead to measurement issues at very low temperatures or in pulsed high magnetic fields.

In a recent paper written by researchers at the University of Warsaw titled “Ultra-long-working-distance spectroscopy of single nanostructures with a spherical solid immersion microlenses,” a 3D printing technique known as direct laser writing (DLW) was used to manufacture microlenses aimed at enhancing long-distance spectroscopy.

The advantages of using DLW 3D printing (which leverages two-photon lithography) include its rapid printing speed. The researchers describe how they were able to 3D print hundreds of microlenses onto a sample. The microlenses were 3D printed in arrays to produce a coordinate system that the researchers used as a map to pinpoint the location of a given nano object. In turn, this capability allowed the researchers to accurately distribute the same experiments to labs all over the world, where measurements could be independently verified.

The research conducted suggests that the 3D-printed microlenses could replace the annoying microscope methodology used to take spectroscopic measurements of atomically small light, emitting samples such as quantum dots.

The distance normally required by researchers using unwieldy microscopes needed to be about a tenth of an inch away from a sample to provide accurate results. This has limitations in different experiments with different environments, such as cryogenic ones or those with problematic electromagnetic characteristics.

The 3D-printed microlenses increase the available distance by more than two orders of magnitude, according to the research paper. This could allow researchers to conduct optical experiments in previously problematic environments.

Bottom Line

The advancement of 3D printing technology (along with advances in material research) continues to open new doors for scientists, engineers and researchers to walk through. The 3D-printed microlenses from researchers at the University of Warsaw could enable new scientific experiments and discoveries.

We’ll just have to wait and see.