As technology progresses, the need for new and innovative solutions to the world's problems becomes more and more apparent; and what is better than a device that kills a few birds with one stone? Memristors are fundamental electronic components that have a special property: their ability to change their resistance when a voltage is passed through them. This phenomena is known as resistive switching, and allows the memristor to keep a "memory" (hence the name, "memory resistor") of the voltage that has been passed through it. This property enables it to perform many functions: they can be used as a switch, to hold memory, and in neuromorphic computing. They are energy efficient, and can be made very small - smaller than what is possible for current transistor technology. This is important, as these devices not only enable us to gain more computing power, but also allow us to use less energy whilst doing it. The problem is that they are currently still very difficult to manufacture, and we still do not know a lot about the mechanisms by which they perform resistive switching. As well as this, their performance is plagued by issues such as leakage currents, low endurance and low "on/off ratio", meaning it is difficult to tell if a memristor is in its high or low resistance state. The performance of the devices is heavily dependent on their size: for example, leakage currents tend to happen to very small devices, as it is easy for electrons to tunnel through the small barrier of the device, or to find some accidental path of low resistance.

This summer, I investigated methods of manufacturing memristor devices, particularly to explore how their performance varies with size in order to highlight the effects that are the cause of their issues. I wanted to reach an optimal size for the "on/off" ratio to become a maximum. 

Initially, the project was exciting. For the first while, my job was to soak up as much information about nanoscience and memristors as possible. I was trained to do chemical vapour deposition, atomic force microscopy, Raman spectroscopy, mask aligning and many more scientific techniques with big names. I read paper after paper discussing different materials used in memristors, different mechanisms by which resistive switching occurrs and about the theoretical limits of how small we could make devices such as these. It was then I realised what a collossal task I had set for myself.  

I felt I was in the deep end: there was a lot to understand, and very little time. On top of that, there were many technical difficulties along the way - machines broke down, and equipment was broken. Although the other people working in the lab who were training and supervising me were very helpful and I could not have completed any work without their help, they weren't always free to train me or to go to a room in CRANN (Trinity's nanoscience institute) with me to help me use an expensive piece of equipment. I felt stuck - the time was slipping away, and not only was I not working fast enough, but the work I was doing wasn't producing the right results. The thin films that we created for the devices weren't growing continuously, the photoresist wasn't peeling off and I was struggling to understand some of the concepts behind the fabrication process. More than that, I felt that I couldn't ask for help, and this was just the nature of research. While it is true that research doesn't always work out, something needed to change.

Honestly, what pulled me out of my slump was talking to my family and some of my fellow Laidlaw Scholars. They helped me to look on the bright side, and helped me regain my determination for the project. They made me realise that while there were some things I couldn't control, there were other things that I could. They also made me realise that even if the research doesn't go exactly to plan, there are always things that you learn from it. Both academically and personally, this project pushed me. I learned about physics, but I also learned how to work with people, how to communicate, and how to ask for help. The goals of my project transformed over time: once I became invested in the process of fabricating memristors, I learned that something seemingly trivial like optimising the heating band temperature for chemical vapour deposition would be a massive help to other people trying to do similar things to me in the future. This gave me another realisation: most of the time, doing research is not really about finding some groundbreaking results that will change the world. Instead, it is about making progress in a specific area, so that it becomes one less thing to think about the next time somebody attempts to do something similar. 

While I was not able to fabricate memristors with high "on/off" ratios, I was able to experiment with chemical vapour deposition parameters, to see what temperatures and gas flow rates were successful in creating films. I also tried different methods of fabriaction, using both photolithography and a shadow mask to create devices - I could then compare the two methods to weigh up the advantages and disadvantages. I even got to run some electrical measurements, and found that there were only small changes to make to create working devices. At the start of my project, I would have seen results like this as something easily obtained, but when I look back now and realise all the work I had to do to obtain these results, I realise that I am proud of the work that I have done. 

While I am still disappointed that fabricating memristors turned out to be very difficult and that I would somehow not win a Nobel Prize before I turned twenty-one, I am still delighted to have participated in the research. I have gotten the chance to work on an area of physics that is likely to change the world, which seemed to me a very fulfilling way to spend a summer. I have learned things that I will no doubt take forward and use in my career, and I have gained a new perspective on acadmemic research.