In this project, we successfully designed and fabricated new 2D liquid cells for dielectric characterization of biomolecules under 2D confinement using scanning dielectric microscopy. The design of the 2D liquid cells is based on the 2D nanochannel design, previously introduced for water’s dielectric properties, which was obtained by patterning and stacking 2D crystals to form nanochannels of controlled thickness. Notably we succeeded to fabricate them despite great disruptions caused by the Covid19 pandemic. This caused the shutdown of our cleanrooms and labs for various months followed by their restricted access for most of the duration of this project.
We successfully carried out the experiments of structural and dielectric characterization of the 2D liquid cells that we fabricated and confined biomolecules using scanning dielectric microscopy. We developed novel numerical models for the 2D liquid cells and the biomolecules, and applied them to interpret our experimental data.
The extracted dielectric properties that we obtained in this project represent an important step forward in our understanding of dielectric properties of biomolecules under strong confinement. To achieve these results, we implemented contingency plans and modified the planning to limit the impact of the Covid19 pandemic, which caused great delays in the experiments. For this reason, the experiments are not fully completed yet. Dielectric characterization of the devices with confined biomolecules is still under progress and publications are in preparation. Notably, during this project, we obtained additional results, which already led to three publications in important peer-reviewed journals of the field in the period (plus one just accepted). In particular, we discovered the emergence of interfacial ferroelectricity in marginally twisted hexagonal boron nitride crystals, an important finding that we published in paper in a Nature journal in the period. This paper was also awarded the prize as best paper of the semester by the Spanish Royal Society of Physics, which gave additional highlight to these findings.
In addition to the dissemination through publications, Dr Fabregas presented the results as speaker to national and international conferences, including the One-Day Meeting for Early Career Biological Physicists 2020 (UK) and the International Conference of Nanoscience and Technology 2021 (Canada). He was also invited to give a seminar at the Department of Applied Mathematics of the University of Granada (Spain) and a course on COMSOL Multiphysics. Dr Fábregas also participated to outreach activities, including the MCAA Annual Conference and the gender and diversity day organized by the University of Manchester.