The design, simulation, fabrication and testing of AFM probes for thermomechanical testing at the nanoscale
Lead Research Organisation:
University of Glasgow
Department Name: School of Engineering
Abstract
The use of Atomic Force Microscopy (AFM) probes to measure the mechanical properties of samples at the nanoscale is relatively well established. In recent years, this technique has been extended by employing Scanning Thermal Microscopy (SThM) probes that enable the simultaneous control of local sample temperature and mechanical loading. However, whilst offering great potential, this nano thermomechanical testing typically generates results with poor reproducibility and large uncertainties. This is due to the fact that current SThM probes are poorly suited to delivering well characterised thermal and mechanical performance.
The aim of this PhD project is to design SThM probes specifically suited to nano thermomechanical measurements. In order to achieve this, the project will be broken down into stages. Firstly, the mechanical and thermal interaction between current SThM probes and samples will be studied through experimentation and theoretical analysis. The insights gained will then be used to identify the strengths and weaknesses of current probe designs. This knowledge will permit a number of improved SThM probes to be designed and evaluated using engineering modelling techniques (e.g. Finite Element Analysis). Finally, the most promising designs will be fabricated and tested using the facilities available at Glasgow. Once fully characterised, these new probes can then be deployed to accurately characterise the thermomechanical properties of novel nanomaterials (e.g. graphene).
This exciting project plays to the strengths of Glasgow University in the areas of Atomic Force Microscopy, Nanofabrication and nanoscale heat transfer. As such, it is anticipated that the results and IP generated will be ideally suited to publication in leading journals as well as possible commercial exploitation.
The aim of this PhD project is to design SThM probes specifically suited to nano thermomechanical measurements. In order to achieve this, the project will be broken down into stages. Firstly, the mechanical and thermal interaction between current SThM probes and samples will be studied through experimentation and theoretical analysis. The insights gained will then be used to identify the strengths and weaknesses of current probe designs. This knowledge will permit a number of improved SThM probes to be designed and evaluated using engineering modelling techniques (e.g. Finite Element Analysis). Finally, the most promising designs will be fabricated and tested using the facilities available at Glasgow. Once fully characterised, these new probes can then be deployed to accurately characterise the thermomechanical properties of novel nanomaterials (e.g. graphene).
This exciting project plays to the strengths of Glasgow University in the areas of Atomic Force Microscopy, Nanofabrication and nanoscale heat transfer. As such, it is anticipated that the results and IP generated will be ideally suited to publication in leading journals as well as possible commercial exploitation.
Organisations
People |
ORCID iD |
| Phillip Dobson (Primary Supervisor) | |
| Christopher Mordue (Student) |
| Description | Better knowledge and understanding of AFM probes thermomechanical behaviour through testing/experimentation and simulation has been performed. This has been utilising SThM probes that measure temperature, alongside act as generic AFM probes, and so the findings provide simultaneous insights into general AFM probes and SThM ones. The findings have highlighted the significance of the thermomechanical behaviour of the probe's cantilever's when constructed out of multiple materials to the overall thermal drift/thermomechanical behaviour of AFM. This behaviour changes when a probe is brought in-contact with a surface during operation for contact-mode where this work strongly supports a change during scanning. The thermomechanical behaviour pertains more towards a bridge, than a cantilever resulting in a fundamental difference. This is a new finding in this topic. This in-contact behaviour has been consistently demonstrated where findings have been shown in how this bridge behaviour can reduce perceived theromechanical behaviour during scanning by changing the laser/deflection measurement point along the AFM probe. Theoretically, 100% thermomechanical bend can be removed from multi-material contact AFM probes, where findings thus far has demonstrated a 98% reduction in a single AFM line scan. With the above finding, it is still desirable to alter the design of AFM probes as not all come in-contact with the surface, the approach a contact probe to a surface is still affected and the point of perceived reduced thermomechanical behaviour can be altered so a wider section to aim for is possible. From this, many designs have been theorised and simulated where one is currently being fabricated and tested for its effectiveness. The findings of which look promising in providing a relatively simple and effective approach for SThM probes. This has been articulated in other AFM probes, but adds evidence to this alongside providing a brand new SThM design. |
| Exploitation Route | Commercial SThM Fabrication Commercial AFM Fabrication Commercial AFM Operation |
| Sectors | Electronics,Energy,Manufacturing, including Industrial Biotechology |