My main research update from this year is that the experiments as part of my PhD have started. This year I have been focusing on the material selection aspect of my work.
To recap, the material aspect of my project can be broken into three stages: additive identification, material selection and material characterization. First, 17 additives were selected which were either metal oxides or metal nanoparticles. The material selection stage of the research involves assessing additives based on their performance and deciding which one performed best overall. The criteria that the additives will be tested under included UV curing, settling and antimicrobial properties.
The UV curing experiments were carried out in February and the data has been analysed. The settling experiments are finished with the analysis in progress and the microbiological tests are also in progress. Once there is a single additive chosen, this will be 3D printed and characterized by mechanical testing and further antimicrobial testing – to make sure that 3D printed parts can kill bacteria.
Design of experiments
One of the most difficult aspects of my PhD journey so far has been planning and designing experiments. Even though it is interesting, it took a long time to get right. Similar to the literature review blog post, the first step is to check if any other published work has been done on a similar topic. For the material selection stage of this project, I am using adapted methods found in literature for my experiments. Each experiment needed to be modified slightly for this project. An important aspect while conducting a research project is being able to justify the methods being used when defending the work.
Undertaking these PhD experiments has been my first time having to think about how best to test anything. During school, my undergraduate degree and Master’s degree, the test methods were always given in advance, for practicality. Because of this, the last three years have involved a huge amount of learning and trying to think in a way I never had to before. It is crucial to design an experiment so that you are measuring exactly what you are trying to measure, since unaccounted for factors can affect the results.
Setbacks with experiments
There have been setbacks with the material selection experiments, some of which are due to poor planning.
A few times experiments have been postponed because essential materials or supplies had not been delivered on time. This is not so bad as there is always other work to be done, such as drafting literature reviews or making literature summaries for future papers.
There were issues encountered while setting up the settling tests. For this experiment, I was taking time-lapse images every hour as the powder settled out of suspension. The main issue was that the light sources I was using as a back light were curing the resin. This resulted in the final experiment using a red LED light source and in a dark box since the ambient lab lighting was even curing the resin. This set back added a few weeks to the experiment overall.
It is important to be able to deal with and overcome these setbacks as part of the PhD process, and learn to not take issues with an experiment personally. This is something that I am still learning to do.