Winners of the RAITH Micrograph Award 2024

For the second year in a row, the Micrograph Award winner comes from France. This year, Saliha Ouendi from the Université de Lille / IEMN impressed us with her work on achromatic metalenses using an EBPG. Traditional optical systems require multiple thick lenses to correct for chromatic aberration, adding size, weight, and complexity to devices like cameras, microscopes, and telescopes. Achromatic metalenses can replace complex stacks with a single thin layer, allowing smaller, lighter optics. However, simple geometries such as discs are not sufficient for such metalenses. To be achromatic, what matters is that each meta-atom achieves a specific variation of its optical response over the entire bandwidth. This requires more complex geometries to be defined in order to increase the total number of structures available. The achromatic metalens shown has a size of 1mm and is defined to focalize the mid infrared light at a distance of 5mm. It is composed of more than 50 different silicon meta-atoms, each of them having finely defined geometries in order to optimize the achromatic behavior.

The second place was awarded to Giuseppe Romano from the Massachusetts Institute of Technology in Boston, MA, USA. Using a VELION FIB-system, he fabricated inverse-designed thermoelectric materials for energy harvesting. He used a computer program to optimize the thermal energy conversion efficiency of the material. Specifically, this system has low thermal conductivity and high electrical conductivity, a key requirement for thermoelectric systems. Applications include waste heat recovery, space explorations (the Voyager probes are powered by a thermoelectric material), and wearable electronics.

The third place goes to Dominik Ludescher from the University of Stuttgart in Germany. Using a RAITH VOYAGER, he developed an optical sieve for nanoplastic detection, leveraging Mie void resonances in high-refractive-index materials.

Plastic pollution is a major environmental issue, with micro- and nanoplastics posing significant risks. First identified in 2004, microplastics are plastic fragments under 5 mm that are directly released or originate from degradation of larger plastics. Over time, they break down further into nanoplastics (under 1 µm), which are more harmful due to their persistence and ability to cross biological barriers, leading to potential health risks.

To address detection challenges, Dominik Ludescher and co-workers developed an optical sieve using Mie void resonances in high-refractive-index materials. These nanosized voids, fabricated by electron-beam lithography using a RAITH VOYAGER followed by dry etching with SiCl₄ gas, change color under a microscope when nanoplastics are trapped inside. Using RGB microscopy, they can detect particles as small as 200 nm. The sieve also isolates nanoplastics from real-world samples, such as lake water. This method provides a simple, effective approach for identifying nanoplastics without complex instrumentation.

As mentioned, we decided once again to include the winning “Honorable Mention” category to showcase other impressive submissions that did not make it into the top three, but still excited us with the quality of their work. Congratulations to Juan Salvador Sanchez from the University of Salamanca in Spain, who designed three graphene superlattices with different hole sizes (300 nm, 200 nm, and 100 nm). Measurement of their electrical properties showed that the superlattice geometry significantly enhances the superballistic effect.

We would also like to congratulate Raphael Gherman (Université de Sherbrooke, Canada), Jelena Wohlwend (ETH Zürich, Switzerland), and Vittorio Apolloni (Padua University, Italy) for winning an Art Award this year.

You can view all the winning micrographs in the gallery here.

Have you also created some impressive work using your RAITH system or attachment? We are always on the lookout and eager to see what exciting things you are working on.

Registration for the Micrograph Award is open all year round, and if you enter a high-quality submission, your chances of winning a fully sponsored trip to a conference are very high! Please note that evaluation is not only based on the quality of the picture, but also takes the scientific motivation and description of the work into account. So if you’ve created some interesting work with your RAITH system, take your chance - and maybe next year it will be you going on a fully sponsored trip to a micro- or nanofabrication-related conference of your choice!