Finished my first week at Nottingham University with very mixed feelings. I have had a solid week reading about my task ahead and feel excited and looking forward to starting the design process. Normally, at the start of a PhD you would expect to do a literature review for at least 3 months but my research is again, a little different to normal. I am basically integrating 3 or 4 optical metrology techniques into a single device so the first part will involve the design of this device in a prototype machine so that teething problems can be ironed out and the control integrated. On the down side, it has been very tiring with early starts to beat the traffic. Nottingham is unbelievably busy during rush hour and I have found that I need to arrive by 7 am to miss the majority of it. When I stay at my Mums it means leaving by around 6.15 am and so getting up at 5.45 am which is not too bad. However, when travelling from MK it means setting off by 5.30 am and so getting up around 5 am latest. I am usually awake by that time anyway, but the pressure is on when you have to be on the road. It also took me the entire week to get online with an email address. It’s starting to look like the administration at Nottingham is comparable to Cranfield. I finally got my email sorted about 3 pm on Friday and had emails dated from the beginning of September. One of them was regarding my funding which I should have been sent to my existing email before I started so that it could have been sorted out prior to starting. The offer I have received is very much lower than expected and I hope that it can be resolved before too long. Of course, my expenses are much higher than Cranfield because of the distance from home. Also, they charge £10 a day parking where its free at Cranfield. I really hope that these problems can be solved so that I can get stuck into the research and design properly.
It’s a beautiful campus and there are two of them, ours is the Jubilee campus but the other one is University park campus which is even more beautiful as it sounds. I will try to get some pictures of the park campus another time. My machine is called an optical-micro Coordinate Measuring Machine (CMM). It will use 3 modern all optical techniques to measure small parts, less than 100 mm cubed and combine the results to hopefully obtain greater accuracy.
The first part uses Focus Variation to measure the surfaces of the part. Consider a flat surface, which is to be measured or examined. A camera focuses below the surface, takes a picture then moves up a touch and takes another picture. Many pictures are taken, starting below the focus point moving up through the focus point to focus above the surface. Each pixel photo series can then be analysed to find the greatest contrast compared to adjacent pixels. The picture with the greatest contrast is the surface so the distance to this pixel is now known. Other qualities are noted such as colour and brightness etc. Once each pixel has been analysed, a complete digital representation of the surface has been made which can be manipulated however required. Basically, this is a colour image microscope that can measure any part of the subject accurately.
The second instrument is called a coherence scanning interferometer which also measures accurately the surfaces of the part. These are generally used for highly reflective machined parts. This will also create areal topography maps with a typical repeatability of 1 nm.
The third instrument method is called stereo photogrammetry which uses multiple cameras to create 3D models and images of parts. This method is mainly used by satellites to model cities etc. but it can also be used to model smaller parts. At Cranfield we used this method to measure the surface shape of solar collectors by placing uniquely identified targets around the collecting mirror. Pictures are taken from many angles and positions and software recognises the uniquely identified targets and so knows where on the surface to picture is. These pictures can automatically be analysed to build up a 3D model of the surfaces. At Nottingham, instead of targets, a random laser speckle pattern is projected onto the part surfaces and the pictures are analysed automatically. Seems to me like one hell of a piece of software to achieve this, but it’s not my responsibility to write it, only integrate these three instruments and design the control between them all.
When making very accurate measurements in the nanoscale the slightest thing effects the results and accuracy of measurements. Differences in temperature between different parts of the machine causes thermal expansion which moves things around. External vibrations can get transmitted through the machine and cause movement when pictures are being taken or measurements made. Normally, such a machine would be mechanically separated from the environment using anti-vibration mounts and very stiff and heavy components inside the machine. Again, a different tact is being used on this machine and the mechanical separation will be via 3D printed lattice structures. This is also relatively new research work and Nottingham has a large additive manufacturing facility and can produce plastic and sintered metal structures that could not be produced in any other way.
My desk 18 is the one at the back left. There is a table behind me so you can stand and work sometimes which I have already used to read on. Just outside research office C19 are a few comfy casual discussion areas so you do not disrupt others when you have a get together. Behind the comfy area is an eating area behind the glass wall. The entire building is only a year old. The feature image and the first one in the text is my building (Advanced Manufacturing). I could become very comfortable here.
Professor Richard Leach who runs this facility has a metrology background and worked at NPL for 25 years. As soon as he had his gold watch, he left to become a research Fellow at Nottingham and set up this facility 3 years ago. I have just become his 40th research student. He set up the additive manufacturing facility where parts could be made that are very difficult to measure conventionally so he started the all optical metrology department to compliment it. To me optical measurement seems like the future and old fashioned measurements where the parts are touched, the past. Richard is incredibly well thought of in these fields throughout the world and is “The Man of the Moment”. I am proud to have Richard as my main supervisor, but another guy called Dr Wahyudin Syam, will be my other supervisor. Wahyudin is responsible for the focus variation research and also the lattice structure research used on my machine. I am personally intrigued by the potential of the lattice structures and can see them being used in many places in the near future. Wahyudin is originally Indonesian but did his PhD in Italy. He has a 1 year old daughter and he and his wife plan to take her home next April to see their parents. He is a really nice chap and has helped me so much this week fighting our way through the administration and personally accompanying me every step of the way. Exciting times ahead, I can’t stop reading about everything, so I can get started as soon as possible. Let’s hope the funding part doesn’t screw things up.