Continuous Rotation Transmission Electron Microscopy Tomography Stage for Imaging/Spectroscopy and In-Situ Characterization of Materials

Electron tomography produces high-resolution three-dimensional views of transmission electron microscopy samples. This microscopy technique is poised to have a leading role in future structural characterization efforts of relevant samples in next-generation electronic and energy storage devices that increasingly rely on small complex 3D geometries to push performance to the next level. Only when one can characterize the materials in 3D space can one understand and optimize their performance as well as the processes that are used to fabricate them. At present, the current limiting factor in the speed and quality of transmission electron microscopy (TEM) tomographic reconstructions is the total runout in the tilt axes on modern transmission electron microscopes. As a result, for every tilt step, one must correct for sample shift, which makes tomographic dataset collection a slow and tedious process. The built-in microscope stage (side-entry goniometer) was simply not designed with the specifications needed to produce high- resolution 3D tomograms quickly and repeatably. Slow acquisition also results in unnecessarily high electron doses which can result in damage to the specimen under observation. In Phase I of this SBIR, Hummingbird Scientific has prototyped a fast, concentric moving (low runout) dedicated tomography sample stage that we intend to commercialize as a replacement internal stage product for any TEM. We have successfully demonstrated the advantages of this approach by retrofitting a working transmission electron microscope with our prototype in Phase I. In Phase II, Hummingbird will design, manufacture, assemble, and beta test this internal tomography stage with a tomography sample loading system and control interface for collecting 180-degree tomograms. The final target is to be able to collect a full tomogram in 60 seconds. Our tomography stage product will take full advantage of the current generation of high-frame- rate electron detectors to collect data of sufficiently high quality as the sample rotates. We will leverage the internal capabilities at Hummingbird Scientific to engineer, build, and test this tomography stage system and to develop the commercial product proposed in this project. We have added a second TEM in our facility dedicated for TEM stage work to enable our technicians to perform routine assembly and testing work on TEM columns to support this project. Materials research groups focused on studying the 3D structure of nano-scale materials would be the main customer of this product. We plan to be in beta testing this product and collecting scientifically relevant data to be used in marketing activities by the end of Phase II