Yimo HAN

Yimo Han is devoted to the development of novel electron microscopic characterization techniques to understand the structure and properties of materials and biological macromolecules at the fundamental science level, which will have important contributions to quantum computing, renewable energy, and drug development. Her main contribution is the improvement of new characterization techniques and to study the nanoscale structure and properties of substances and provide an important scientific basis for the design and synthesis of new materials and molecules.

Her representative achievements include the discovery of one-dimensional channels in two-dimensional materials through atomic-resolution scanning transmission electron microscopy imaging, and achieving sub-nanometer coherent heterojunction structures that can be controlled via dislocation engineering, thus paving the way for applications in nanoelectronics and optoelectronics.

Han also developed a strain mapping approach using nanobeam four-dimensional scanning transmission electron microscopy (4D-STEM). This decoupled the spatial resolution from mapping precision, enabling strain and dislocation mapping in materials across microns.

Using her background in materials science, Han used a single layer of functionalized graphene as the supporting film to improve the sample preparation for cryo-EM, which enabled the highest resolution (at the time) for a small protein, 2.6 Å resolution for a 52 kDa streptavidin. This method can greatly benefit cryo-sample preparation and enhance the resolution for future cryo-EM studies.

Han recently used machine learning approaches to automate methods such as electron ptychography and strain mapping, which can significantly speed up and reduce the complexity of these data sets, such that non-experts are able to interpret the data.