Lateral Force on Fingertips by Traveling Waves in a Flat Structure Based on the Ultraloop

Creating a lateral force on a finger touching a touch- screen can provide the sensation of a bump in the surface, and generate a pulling sensation, which could enhance the experience of operating a touchscreen. The Ultraloop, a device built to generate such a lateral force on a finger in contact, works by producing flexural traveling waves that...

Mechanical design for out-of-plane mode attenuation in flexure mechanisms

The most problematic eigenmode in machines involving flexure mechanisms is represented by flexural modes. However, it can be noticed that also out-of-plane modes, that occur in the space outside the nominal plane of movement of the mechanism, can be very important, especially in machines with several and coupled degrees of freedom, like 3D...

Efficiently coupling QM and MD for the study of electrode-electrolyte interfaces

In this thesis, a proof of concept was established for the use of a novel coupled QM-MD approach to modelling metallic (copper) electrode-electrolyte interfaces. SCC-DFTB calculations of the instantaneous electronic structure of a copper electrode were coupled to a classical MD simulation of an electrode-electrolyte interface. The applied QM-MD...

Design and tuning of a bi-stable compliant mechanism: For use in energy harvesting using frequency up conversion

Vibration energy harvesting is a growing field of research. Harvesting energy from vibrations can be of use in devices in hard to reach places, such as sensors on a train track or a pacemaker. These devices makes use of batteries, which need to be replaced. Using energy harvesting this battery life could be improved. <br/>The difficulty lies in...

Piezoelectric energy harvesting from low frequency vibrations

Vibration energy harvesters have been proposed as a solution to increase the lifetime of wireless and portable medical devices. One example of implantable medical devices for which energy harvesters could be interesting, are pacemakers. With a lifespan of about 6 to 12 years, the battery must be replaced after this period of time. Using an...

Design of travel limits for bistable vibration energy harvesting

Energy harvesting from renewable energy sources has become more popular in the last decades than ever before. New energy sources consisting of human input vibrations are hopeful alternatives for powering wearable low power electronics. These sensors currently rely on the lifetime of the battery and come along with high maintenance costs in case...

Direct or Indirect?: Unraveling the bandgap nature of metal halide perovskites

Since the discovery of the photovoltaic properties of metal halide perovskites in 2009, the material has rapidly gained interest in the scientific community. In less than 10 years, the power conversion efficiency of perovskite solar cells (PSC) has increased from 3.9% to over 25%, reaching levels of conventional silicon cells. PSCs have multiple...

Modelling viscoelasticity using Multifrequency AFM

Viscoelasticity is a material property that is relevant in a variety of nanoscale materials and interfaces in medicine and industry. Therefore, a method of mechanical quantification has become exceedingly desired. In this thesis the Atomic force microscope (AFM) is applied to accurately characterize the mechanical behavior of viscoelastic...

A Complete Overview on Realizing Transfer-free Graphene-based Differential Pressure Sensor

Graphene is an attractive material to be used for pressure sensors due to its thinness, electrical conductivity, and potential high gauge factor. One of the issues with processing graphene is the scalability, which is largely limited by the transfer process that is required for graphene deposited by chemical vapour deposition (CVD). In this work...

The design of a monolithic, compliant, resonant running robot at insect scale

Running robots at insect scale are an upcoming research field, because of their numerous potential applications like exploration of hazardous environments such as collapsed buildings, natural disaster sites and debris. To date no report exists on such a robot that either exploits its resonance, or that is monolithic. These properties, however,...

Simulations and experiments on coplanar waveguide resonators intersected by capacitively shunted Josephson junctions

A single photon interacting with a single atom is the most fundamental form of light interacting with matter and has been extensively studied in the field of Cavity Quantum Electrodynamics (cavity QED). Here, a non-linearity like an atom is coupled to a single mode of the electromagnetic field in a cavity. Another field which explores the...

Optical refrigeration under laser and solar irradiation

The concept of optical refrigeration dates back to 1929, when Pringsheim recognized that thermal energy associated with the translational degrees of freedom of isolated atoms could be reduced by the process of anti-Stokes fluorescence. Optical refrigeration of a solid was first experimentally demonstrated in 1995 with the Ytterbium-doped...

Design of a Setup for Modal Testing of Micro-Cantilevers Immersed in Liquid

To facilitate research on the dynamics of micro-cantilevers immersed in liquid, a modal test setup was designed. Modal testing is a powerful form of dynamic testing whereby the system's natural frequencies, modal masses, modal damping ratios, mode shapes, and weight of each of these modes at a certain frequency are determined. Micro-cantilever...

Tip identification in atomic force microscopy using nonlinear dynamics

Since its invention, the Atomic Force Microscope has emerged into one of the most useful tools in<br/>nanotechnology due to its acclaimed abilities in exploring surface topography, micro- and nanoscale manipulation<br/>and characterization. The nonlinear interaction between the cantilever tip and the sample surface<br/>has been studied in great...

Extracting elastic properties of graphene nanodrums using a multi-modal approach in Molecular Dynamics

The field of nanotechnology has been quickly growing over the last few decades and many different functional Nano Electro Mechanical Systems(NEMS) can now be made. <br/>To further increase the possibilities and functionality of NEMS, new materials have to be characterized. Of the new materials which become available at the nanoscale, graphene is...

Optimized MEMS-based Nanoreactor for In-Situ Transmission Electron Microscopy Studies at High Temperature and Atmospheric Pressure

Transmission electron microscopy is a powerful and commonly used tool to study nanoparticles, nanowires and 2D materials. It provides static information from the sample with atomic resolution, in high vacuum and at ambient temperature. However, in real processes, the environment is often different and dynamic.<br/><br/> MEMS-based sample...

Damage detection in semiconductor devices by non-linear elastic wave spectroscopy

Semiconductor devices can be found everywhere in our daily lives, for example in self-driving cars, bank cards and personal devices such as smart phones or notebooks. Once part of these personal devices, one does not want them to show failure. Although reliability of such devices is taken into account in the design, the fabrication process might...