Previous Research Topics

The research topics listed here have been the subject of previous research grants, but we not currently studying these through funded projects. This information remains on this website as these are topics which we may very well pursue again in future grants.

Topics on this page:

Thin-film metrology


The requirement to be able to accurately measure the thickness of very thin films has existed for a large number of years and in a diverse range of industries. Companies in the food, beverage, paper, foil/film converting and pharmaceutical industries all require accurate measurement systems to be able to carry out process control in-line and in real time.

A DVD - Measuring the thickness and surface profile of thin films on consumer items like DVD's is big business...

The big advantage of being able to continuously monitor the film thickness is a reduction in the production costs coupled with an improvement in the product quality. In-situ measurements are carried out in real time and results can be fed back into the coating process to improve the quality. When a measurement is taken from a sample in the lab, it is only after the technician has reported back with the results that any change can be made to the coating process, by which time more product has already passed through the process. If the results from the sample are not of a high enough quality then the product already passed through the process will have to be scrapped. This results in a higher cost of manufacture. The active feedback from the in-situ measurement will reduce this level of scrap, as it will be able to react to the changes required before any more product is passed through the process. This will reduce the amount of scrap product generated and cut costs dramatically for the manufacturer.

Our research

Our previous research project was to develop an industrial film thickness sensor for use in a diverse range of applications. The requirements were that it needed to be accurate, reliable, able to be used to measure multiple layer laminate film structures, with coloured and rough samples and be able to be mounted in-line to carry out in-situ real time thickness measurements during the printing process. When the sensor is mounted in-line it would have to be able to cope with high line printing speeds and possibly movement of the printing web itself. In addition to this we wanted a sensor capable of providing detailed information on the surface shape and surface roughness of the material under test. The main areas being targeted using this new type of sensor were the plastics coatings industry, the semiconductor industry, the optical coatings industries and the ophthalmic industry.

Our simple thickness monitor was shown capable of assessing layer thickness in laminate structures with a total thickness of up to 8mm and with individual layers down to 3μm thickness provided that at most one of the layers is optically rough.

We also applied this to ophthalmic measurements, and filed a patent on this application, in collaboration with AMO Inc.

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Optical aperture synthesis

Optical Aperture Synthesis (OAS) offers the possibility to achieve surveillance images with more than 100x the information content or 10x the range of current equipment. Our research in this area included an initial study of the risks associated with implementation of OAS in military applications and examined both passive and active synthesis imaging methods. Previous studies within this programme identified the active technique of Fourier Telescopy as the most promising mid-term solution and we built a basic-level laboratory demonstration of a Redundant Spacings Calibration (RSC) method to calibrate atmospheric errors in such a system.

The predictions of the SNR as a function of source strength have been tested on the laboratory instrument and we are looking for ways to produce accurate, printed, sinusoidal charts with variable resolution and contrast in order to complete this assessment.

For more information....

Visit the aperture synthesis page within the resources section. This includes useful references and suggestions for further reading.

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Our Research

Find information on our current research projects, and our research interests both past and present...

Life Sciences Interface