To improve the sample production several measures could be taken. In
order to obtain more reliable results a higher number of samples should be
produced and measured.
The first observed problem in this project is when I tried to apply
voltage to polarize the sample, the sample got holes at the centre. Hole is
formed because of high voltage passed through electrodes on the sample. For
high voltage electrodes thickness is not enough, so we increased the thickness
of electrodes on the sample. And also make sure NAOH solution is pure.
Otherwise it causes decrease of resistance in the sample.
The second observed problem is noise because of disturbance in
frequency. Disturbance can be caused by any loose connection. Then I checked
all the connections, found the loose connection and then fixed it. The problem is solved
and we got the expected results.
The third observed problem is of decrease in polarization at the ends of
the sample. When I checked thickness of the sample in different places then I
got to know where the problem is, Centre of the sample thickness compared to
ends of the sample the thickness is not same. This problem is solved in the
next sample by making sample without any small changes in thickness all over
Bi and multilayer films produced from PVDF and P (VDF-TrFE) with
different molar ratios. Measurements of pyroelectric distributions are done
using LIMM (Laser Intensity Modulation Method) at room temperature. Analyzed
the polarization results using MATLAB. This was done in order
to get an understanding of multilayer systems in general. Moreover,
expectations on the behavior of multilayer systems based on ferroelectric
polymers could be developed.
Data could not be obtained from all multilayer configurations and some
values do not meet the expected results, which show that the sample production
has to be improved. Bi layer polarization decreases if the thermal wave moves deep inside
the sample. Observed different molar ratios presents different polarization
results. Measurements have to be done to know which molar ratio exhibits
maximum polarization and behaviour of polarization at different temperatures.
To summarize, the production of polymer based multilayer systems based
on P (VDF-TrFE) was successful and some properties were characterized. Further
experiments will lead to a better understanding and may help to develop models
which describe such multilayer systems.
On this page I want to thank all the persons who supported me during the
last years of my studies and especially the last months in which this thesis
First of all I like to give thanks to Professor Ploss who gave me the
opportunity to do internship and theisis to career development. He has always
been a patient consultant concerning organisational and field specific issues.
For the support in the laboratory and his helpfulness at any time I like
to say thanks to my mentor M.Sc. David Smykalla, whose assistance during the
whole master’s thesis phase was of inestimable value.
I also want to thank my family for the motivational and financial
support in the last years.
Many thanks go to my friends and fellow students, who provided the
necessary distraction throughout the semesters and helped me to also grow