Electrical Impedance Spectroscopy (EIS) consists in the application of a small voltage or current to a material, varying its frequency in a wide range and measuring its response to the estimulation. In this sense, the spectral behavior of the observed substance is obtained, as for each discrete frequency point one value of impedance is measured.Specifically when applied to biological systems it is called Bio-Impedance Spectroscopy (BIS).This research is about applying EIS to biological systems in order to characterize them. pleasure to work with you! I would like to thank all my colleagues Jonas, Pablo, Julian, Christian, Anton, Kim, everyone with whom I have been working together during the last years. You made my days a bit more funny in this hard work of doing a PhD! A very deep acknowledgement to Mrs. Doris Cornils coordinator from ProExzellenzia Programm 4.0 for providing me with the financial means to complete my research and giving me the honor to participate in the leadership training programm offered by Pro-Exzellenzia. Thank you for your courage to fight for a more equalitarian German society.Without your support this PhD would never have come to reality. Also my big thanks to Dr. Monika Hein my coach, for her advices, patience, open ears to help me become not v only an excellent researcher, but also an inspiring leader. And thanks also to the whole ProExzellenzia team, for all the hours and hours of trainings which turned myself in a better woman, both personally and professionally. This acknowledgment section would not be complete without thanking Ronald Mielke, Ute Schmidt and Silke Bade for all your support with software, network problems, laptop, 3D printing, developing sensors, burocracy. I have no words to thank you for your selfless help to my research. It was also my greatest pleasure to work with all of you! Lastly, I would like to thank my brother and parents, my parents in law, my husband and my three little angels for making my life much happier and full of sense, for your smile and small gifts which made hard days easier and gave me a purpose and sense to keep going forward and fighting.