Semester Projects
(can be adapted to Bachelor or Master level)
Modelling of electric field induced effects in thin dielectrics
AvailableUnderstanding switching dynamics and domain evolution of ferroelectric materials in correlation with modification induced by in-situ biasing is fundamental for the development of devices. Solving partial differential equations in two or three space variables opens up the solution to numerous problems whose areas of interest range from structural analysis, heat transfer, fluid flow, mass transport, and electromagnetic potential. A tool for solving these equations is the Finite Element Method (FEM). The aim of the project is the modelling and calculation of electric field induced profiles on thin membranes of dielectric materials in order to predict their response during in-situ TEM experiments. In a second phase, the student will evaluate the projected electric field in the system in various configurations.
Contact: Mr. Pierpaolo RanieriMEMS-based chips for in situ TEM applications
Not availableThe aim of this project is to fabricate MEMS-based chips for in situ TEM applications such as biasing, heating, and electrochemistry. The student will be introduced to MEMS technologies such as photolithography, etching process, thin film deposition, etc. The process of the chip fabrication will take place in the cleanroom at the Center of Micronanotechnology (CMi). The student is expected to understand the fundamentals of MEMS technologies and obtain hands-on experience of semiconductor processing. The MEMS processing skills obtained after this project are highly transferable especially in semiconductor industries. Previous hands-on experience in cleanroom is preferred for this project.
Contact: Mr. Morgan BinggeliPreparation of rechargeable battery electrodes and their cycling in microcells
ReservedThere is significant research dedicated to rechargeable batteries with the current technology based on lithium ion processes remaining the candidate of choice for further enhancements. These include cathode electrodes based on novel materials due to the fact that the degradation of the cathodes remains the main reason for capacity decay. Electron microscopy experiments can provide unique insights into the degradation processes and can be performed in real-time, however the modification of the bulk cell to a microcell configuration requires optimisation of the system. In detail, the student will work on the battery assembly that includes the ink preparation for the cathode and counter electrodes, the dropcasting, the evaluation of adhesion to the current collector, and its cycling ex-situ at the first instance.
Contact: Mr. Morgan BinggeliMicrofabrication of chips for graphene membrane-based microcells
ReservedThe aim of this project is to fabricate MEMS-based electrochemical chips with integrated graphene membrane for high-resolution imaging in liquid-phase TEM. The student will be introduced to microfabrication processes inclusive of photolithography, thin film deposition, dry and wet etching. The student will acquire hands-on experience in MEMS fabrication processes. Previous hand-on experience in cleanroom is preferred for this project.
Contact: Ms. Saltanat ToleukhanovaModelling of temperature profiles in MEMS-based heating chips
AvailableHaving a homogeneous temperature profile across MEMS chips is very important for the interpretation of the the various processes that are affected by temperature changes such as diffusion of chemical elements and stability of phases. However, this is challenging to achieve at the scale of TEM experiments (micro to atomic scale). The students will use COMSOL software to simulate full MEMS-chip. The aim is to change the geometry and evaluate the optimal geometry of the heating contacts with respect tot he sample placement for achieving homogeneity during the experiments.
Contact: Mr. Pierpaolo Ranieri and Dr. Saul EstandiaSEM imaging of Cu nanocatalysts under CO2 electroreduction conditions
AvailableStudying catalysts’ restructuring behavior under CO2 reduction conditions is important for identifying their degradation mechanism. Liquid-cell electron microscopy allows real-time imaging of materials under controlled biasing conditions. The aim of this project is to study Cu nanocatalyst restructuring behavior under CO2 reducing conditions. In the first part of the project the student will perform a series of control experiments to identify the best imaging conditions for graphene-based liquid cells. In the second part, the student will perform imaging of nanocatalysts under CO2 reducing conditions to track their morphological evolution. The student will gain hands-on experience in SEM operation, liquid electrochemical microcell processes and analysis of SEM data.
Contact: Ms. Saltanat ToleukhanovaSimulating atomic defects in Bi2Se3
Available3D topological insulators like Bi2Se3 possess spin-locked conducting states at their surface which could find applications in spintronics, optoelectronics or quantum computing, among other fields. However, in practice, the presence of crystal defects arising from Bi-Se off-stoichiometry introduces a non-polarized current component, which hinders the potential of the material. This can be observed locally by means of transmission electron microscopy (TEM). In this project, the student will use JEMS and DrProbe software to simulate the atomic distribution of defects under different electron imaging conditions.
Contact: Dr. Saul Estandia