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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Nové organické polovodiče pro bioelektroniku / New organic semiconductors for bioelectronics

Malečková, Romana January 2020 (has links)
This thesis focuses on the characterization of PEDOT:DBSA, a new semiconducting polymer for use in bioelectronic devices. It also deals with possibilities of surface treatment in order to enhance its biocompatibility and stability in aqueous environments. For this purpose, the organic polymer films were crosslinked with two crosslinking agents – GOPS and DVS. The ability of these agents to prevent leaching of some fractions of the polymer films in an aqueous environment and the ability to bind polymer molecules to each other as well as to the glass substrate was studied using the delamination test. Subsequently, the effects of these crosslinking agents on the film properties essential for the proper functions of bioelectronics made of these materials, was studied by contact angle measurements and four-point probes respectively. Moreover, several OECTs were prepared using original and crosslinked material as an active layer and were characterized by measuring transconductance and volumetric capacitance. PEDOT:DBSA has been shown to be a suitable material for use in bioelectronics, but its thin layers need to be stabilized in an aqueous environment. The agent DVS appears to be unsuitable for this purpose, mainly due to its insufficient film stabilization and its increased hydrophilicity of the film surface, thus increased tendency to interact with water, resulting in degradation of these thin layers. In contrast, GOPS, despite some reduction in film conductivity, has been able to stabilize the polymer layer over the long term, and thus appears to be a suitable way to stabilize PEDOT:DBSA.
2

Vývoj senzorické platformy pro studium fyziologických funkcí buněk / Development of a sensing platform for the study of physiological functions of living cells

Marková, Aneta January 2018 (has links)
The aim was to develop a sensing platform on the base of organic electrochemical transistor (OECT). The focus was on the preparation of proper electrode system and on optimalization of properties of thin layer of organic semiconductor. As a base, commercial glass substrates with integrated indium-tin oxide electrodes were chosen. Thin layers were prepared from organic semiconductor poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) by spin-coating. Four formulations of material were studied. Layers with different thickness were prepared and the dependence of transconductance on the thickness of the layer and ratio of width and length was observed. The degradation of electrode system was solved by galvanic plating with gold. Attention was also paid to modifications to PEDOT: PSS. It has been found that the optimal layer thickness for use in sensors is approximately 150 nm. By reducing the series resistance by using a silver paste, the transconductance of 23 mS was obtained for the Ink 2, for the Ink 3 the transconductance was 44 mS. Sensoric platforms with these transconductances can be used for detection of physiological functions of electrogenic cells, e.g. cardiomyocytes.

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