Lens combination for biomedicine Tiny magnetic field sensor with great potential In the Nano-Argovia project ACHROMATIX, an interdisciplinary In the Nano-Argovia project Nanocompass, researchers have team has developed a novel lens system that can be used for developed a novel, nanoscale magnetic field sensor that can be transmission X-ray microscopy. The lens combination is in- manufactured industrially and is expected to find applications tended to compensate for the so-called chromatic aberration of in numerous fields such as quality control or medical technol- different lenses and should be suitable for biomedical analyses. ogy. The magnetic field sensor is tiny, measuring less than 100 The researchers first calculated theoretically which lens com- x 100 nanometers. Therefore, many of these sensors can be bination was best suited for the X-rays used. Using state-of-the- combined on a single chip along with their conditioning and art nanofabrication techniques, they manufactured, character- processing electronics. In addition, the power consumption is ized and tested the different X-ray lenses in order to identify low for a tiny sensor like this. In their approach, the researchers the optimal combination. combined the so-called fluxgate principle, which has so far been Cooperation with: XRnanotech GmbH // Paul Scherrer In- used mainly for macroscopic sensors, with a spintronic device stitute // Biomedical Science Center, University of Basel based on the rules of quantum mechanics. Project description: http://bit.ly/3HY8XVs Cooperation with: Camille Bauer Metrawatt AG // FHNW School of Life Sciences // FHNW School of Engineering Project description: http://bit.ly/3Yq17ed Colorized scanning electron micrograph of a high-density array of 100 nm magnetic tunnel junctions used as nanoscale magnetic sensors. (Image: FHNW) “The Nanocompass project has opened up new perspectives for us in energy measurement technol- ogy, especially in the contactless determination of electrical currents.” Max Ulrich, Managing Director at Camille Bauer Metrawatt AG The lens combination developed in the Nano-Argovia project ACHROMATIX optimizes transmission X-ray microscopy. (Image: J. Vila Comamala, Paul Scherrer Institute) SNI Annual Report 2022 37